Gold placers and placering in Arizona

              GOLD PLACERS AND PLACERING
IN ARIZONA
by
Eldred D. Wilson
Bulletin 168
Reprinted 1981
- State of Arizona
Bureau of Geology and Mineral Technology
Geological Survey Branch
A Division of the University of Arizona
PREFACE TO BULLETIN No. 142 ....
Copyright © 1961
The Board of Regents of the Universities and
State College of Arizona. All rights reserved.
TABLE OF CONTENTS
PAGE
PREFACE 8
PREFACE TO BULLETIN No. 160 . 8
9
PART I
ARIZONA GOLD PLACERS
GENERAL FEATURES OF GOLD PLACERS ...........................•.........•...........•....... _... 11
Origin 11
Distribution of Arizona gold placers.................................................... 12
Relatipn to pediments 12
Relation to streams 14
Relation to geology and types of veins.................................................. 14
Yearly rainy seasons of Arizona.............................................................. 15
HISTORY OF ARIZONA GOLD PLACER MINIm;.................................................... 15
Summary 15
Early production 15
Production after 1900 16
YUMA COUNTY ....•...................•.............•.•.••••...•••••••.••.••••.••••••..••..••••••••.•••••••••••••••• 18
Districts 18
Production 18
Gila City or Dome placers 18
I, aguna placers 21
Muggins placers 22
Castle DOIne placers 23
Kofa or S. H. placers.................................................................................. 23
Tank Mountains placers 24
Trigo placers 25
La Paz placers 25
Plomosa. district 29
La Cholla placer area 29
Oro Fino placer area 30
Middle Camp placer area 31
PIOlnosa placer area 31
Harquahala placers 32
MOHAVE COUNTY ............•...................••.........•...........•••.•.••..•.••...•......•........•..••••..• 32
Districts and production 32
Chemehuevis placers 32
Silver Creek placers 33
Lewis placer 33
Lookout placers 34
Wright Creek placers 34
Colorado River placers 34
Gold Basin placers 35
IGng Tut placers 37
YAVAPAI COUNTY ••.......................•......••.•••..•.••••..•••.•.••_ ••••••••••••....••. _................... 38
Introduction 38
Early History 38
Production 39
Arizona Geological Survey
The Arizona Geological Survey ( AZGS) became an independent State
agency July 1, 1988 in accordance with Senate Bill 1102, which was
enacted in 1987. The purpose of the AZGS - to assist the wise use
of lands and mineral resources in Arizona by providing scientific and
investigative research and information - was essentially unchanged.
The ancestral AZGS began in 1881, when the Office of the Terri­torial
Geologist was established by the Territorial Legislature. The
primary duties were to collect and provide information about mineral
resources. In 1893 the University of Arizona established a testing lab­oratory,
known informally as the " Bureau of Mines." From then until
statehood in 1912, Territorial Geologists were also affiliated with the
" Bureau of Mines" and the university. A 1915 statute formally estab­lished
the Arizona Bureau of Mines as a State agency administered by
the University of Arizona, continuing, essentially unchanged, the func­tions
of the " Bureau of Mines" and. the Territorial Geologist. Data
collection and research activities continued to be · concentrated on
mineral resources. Sixty- two years later, in 1977, the Bureau's enabling
legislation was modernized and its name was changed to the Arizona
Bureau of Geology and Mineral Technology. It continued to be admin­istered
as a diVision of the University of Arizona. The Bureau was
charged with investigating geologic hazards and limitations, as well as
the geologic framework and mineral resources of Arizona, in anticipil­tion
of population growth and increased competition for and conflict
over land, mineral resources, and water.
The AZGS publishes maps, books, and reports, which are available
for inspection at the AZGS office in Tucson and may be purchased
through the mail. The AZGS office includes a library that is open to
the public during normal working hours. Arizona Geology, published
quarterly by the AZGS, contains summaries of AZGS research,
announcements of new publications and theses, and short, general­interest
articles on the geology of Arizona.
To obtain copies of this publication, contact the Arizona Geological
Survey, 845 N. Park Ave., Tucson, AZ 85719; ( 602) 882- 4795.
12- 88UASOO/ 1839
GOLD PLACERS AND PLACERING
IN ARIZONA
Arizona Bureau of Mines*
Bulletin 168
1961
( reprinted 1981 and 1988)
" currently the Arizona Geological Survey
~ e~~ e; r:~~ tifc~ r~ Ii" ii"'" i~~~~~''''''''''''''''''''''''''''''''''' .
~~~:~;~:~~~~~ fi::=~ · :::~:::::::::::::~::::~::~~~:::::::::::::::::::::::::::::::::::::::::::::::::::::
Groom Creek placers __ __ _._.~~~~~~~:~:~::::~:~::~:~~::::~~~:~~:~:~:~:.~ ..
Walnut Grove placers .
Minnehaha placers .
~~~~ l t~~~ e:~ p" i~~~~~ ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
Granite Creek placers ,.
Eureka placers .
Humbug placers ..
other Yavapai placers ::::: ,
39
43
46
48
52
52
54
55
55
56
56
57
57
57
SANTA CRUZ COUNTY 81
Production 81
Oro Blanco placers 82
Patagonia or Mowry placers 83
Harshaw placers 83
Tyndall placers 83
Nogales placers 84
Palmetto placers 84
COCONINO, NAVAJO, AND APACHE CoUNTIES , · .. · · .. · · · · · · · · · · · · · · · · · · · · · · · 84
REFERENCES CITED IN PART I 85
PINA~ t~~ J~~ ro~ · · · :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: ~~
anada del Oro or Old Hat placers 61
GRAHAM COUNTY 65
~ fad~ i~~~ pi";;~.~~~........................................................................................ 65
...................................................................................... 65
G, u ~~~~:~ i~ J~;;~~~-~_ •-. i! Payson placers 63
...................................................................................... 64
PART II
90
87
87
87
87
88
88
88
88
88
89
89
87
SEEKING PLACER GOLD ....,. --_ ~ ~ .. , ~ , - -..
SMALL SCALE GOLD PLACERING
FACTS ABOUT GOLD .
Identification of placer gold , .
Color .
Specific gravity .
Mallea bility and ductility .
Solubility .
Physical properties of gold .
Gravity concentration .
Amalgamation .
Interfering factors .
Size of gold particles .
INTRODUCTION .
58
58
58
59
60
61
MARICOPA COUNTY -- - ---.-- _-.-.- .
t~! t~~~~~~~~ · ~~~~~~:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
Hassayampa placers .
Other Maricopa County placers :::::::.::::::::::::::
GREENLEE COUNTY 65
CPrloifdtounc- tiMonorenci , placers . 65
............................................................................ 65
COCHISE COUNTy .................._- -_ .
E1;~~~ i~~~ c~~~~~;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: .
g~ fJh~~~ chl~ l~ cse~ · · · ~ i;~~~::: ii:~~~ i~:::::::::::::::::::::::::::::::::::::::::::::::::::::::::
~~:~~~ n J~~~~ rs : ~::::::::::::::::::::::::::::::::::::::::::::::::::::::::
••••• _ •• _ _. _' ••• ' u ~.~~ •••••••••• ~ •••• ~ •••••••• ~ •••• ~ ••••
PIMA COUNTY .......~~ ~"' ..~ ..~~~ ~ ~ ~.~ ~ _ .
Production
~! j~~~~ r;~~~~~~~ i::~~~ i~~~::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
~~~ a: l~: A~:~~ t~ · · Pi"~~~~~ · · · · · · :::::::::::::::::::::::::::::::::::::::::::::::::::::::: .
~~ oa;~~: rl~ f:~: r~ · · · · · · · · · · · · · · · · · ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
~~~:~ ~:~ o~ o~~~~ er~;~~~~~::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
67
67
67
69
69
70
70
71
71
71
72
77
78
80
80
80
81
81
81
PLACER EQUIPMENT AND METHODS 91
Gra\' ity concentration 91
Panning Utensils 91
Pan, miner's 91
Batea 91
: Miner's spoon 92
Other panning utensils 92
Panning 92
Cleaning concentrates 93
Amalgamation 93
Copper amalgamating pans 94
Instructions for amalgamating copper pans 94
Panning with an amalgamated pan 94
Quantity of gravel that can be panned in eight hours............ 96
Rocker ( Cradle) 96
Capacity 96
Construction details 96
Apron 98
Riffles 98
Hopper or screen box ,....... 98
Slope of bottom 98
Amalgamation 99
APPENDIX
SUGGESTED LIST OF EQUIPMENT FOR PROSPECTING IN THE SOUTHWEST 118
Prospecting tools 118
General camping equipment 118
Cooking equipment 118
Medical and first- aid supplies 118
~ l~~_ t~::.~~:::~~~~:~:~:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: 1~~
Construction details for knock- down rocker 100
The Long Tom ...................•............................•.............::::::::::::::::::::::::.::::: 100
Operation : : 101
Sl uic~ 1ffl~~ :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: i~~
Slope 104
Water consumption and capacity 104
Amalgamation ....•................................................................................. 105
Clean- ups 105
Small sluices ..........................•............................................................. 105
Wet Methods vs. Dry Methods 107
Dry Concentration 108
Dry Concentrators 109
Blanket 109
Dry panning and blowing 109
Dry- washers 109
Separating Gold from Golci Amalgam III
Retorting III
Retorts III
Charging an amalgam retort 112
Potato method 114
Nitric acid method 115
TABLES AND CONVERSION DATA....................... 116
ILLUSTRATIONS
51
36
38
40
45
46
49
53
60
68
95
103
110
113
13
14
24
27
74
92
92
92
97
101
105
106
107
112
VI.- GOLD STAR COMPANY PLANT, COPPER BASIN .
6. - PAN, GOLD MINEH'S
14. - LONG TOM
PLATE
FIGURE
PLATE VII.- AINLAY BOWL CONCENTHATOR, PANTLE BROS. LEASE, BIG
BUG CHEEK .
PLATE VIlI.- NUGGETS FROM YAVAPAI COUNTy .
PLATE lX.- TypICAL PLACER WORK ON SAN DOMINGO WASH · · · · ·
PLATE XIlI.- DRY- WASHER .
PLATE XIV.- RETOHT ( HOMEMADE) .
FIGUHE 1. - INDEX MAP SHOWING LOCATION OF ARIZONA GOLD PLACEHS
FIGURE 2. - IDEAL CHOSS- SECTIONS OF MOUNTAIN PEDIMENTS .
FIGUHE 3 - GEOLOGIC MAP OF KOFA OR S. H. PLACER AREA..
PLATE X.- GOLD GULCH MINING COMPANY OPERATIONS, TEVISTON
DISTRICT .
PLATE XI.- ROCKER IN OPERATION .
PLATE.. XII.- SMALL SLUICE IN OPERATION .
FIGUR~; 7. - BATEA
FIGUHE 8. - SPOON, MINER'S .
FIGURE 9. - ROClU; R, KNOCKDOWN .
PLATE L- MoTOR- DHIVEN DRY- WASHER, SEARLES GROUP, GOLD BASIN
PLATE Il.- SAMpLING OPERATIONS IN KING TUT PLACERS .
PLATE IlI.- DREDGING OPERATION ON LOWER LYNX CREEK. .
PLATE IV.- TypICAL GRAVELS OF WEAVER CREEK PLACERS .
PLATE V.- Top OF RICH HILL .
FIGUm: 4. - GEOLOGIC MAl' OF pAHT OF DOME ROCK AND PLOMOSA
MOUNTAINS . .
FIGURE 5. - GEOLOGIC MAP OF GHEATERVILLE PLACER AREA ..
FIGUHE
FIGUHE 11. - RIFFLES .
FIGUHE 13. - SLUICE LAY- OUT
FIGURE 14. - RETOHT
FIGURE 12. - SLUICE BOX, SMALL .
116
116
116
116
117
117
Troy weights and equivalents........... . .
Troy weights and measures .
Equivalents .
Liquid volume and capacity equivalents .
Weights of materials .
PART III
SELLING GOLD .
OpEHATIONS DURING 1951- 1961 119
ARIZONA PLACER PRODUCTION 1951- 1959................................................... 120
INDEX 121
PREFACE
Although the yield from placers in Arizona has been relatively
small through the past several years, public interest in gold in­creased
greatly in 1960, and the Arizona Bureau of Mines now re­ceives
numerous requests for information concerning this precious
metal.
The Arizona Bureau of Mines Bulletin No. 160, Arizona Gold
Placers and Placering, Fifth Edition, Revised, was published in
1952. However, it has not been available for general distribution
since 1959.
This present Bulletin No. 168 supersedes Bulletin No. 160 in
the publication series of the Arizona Bureau of Mines inasmuch
as it represents a thorough modification of the subject matter of
the earlier bulletin and, also, it contains supplemental information
which serves to bring statistical data up to date.
J. D. Forrester
Director
October, 1961
PREFACE TO BULLETIN NO. 160
The Arizona Bureau of Mines Bulletin No. 142, ARIZONA
GOLD PLACERS AND PLACERING Fourth Edition which W3S
written in 1933 and republished in 19: 31, has been out ' of print for
the past two years.
For 1932 to 1950, the output of placer gold in the State was
more than d? uble the amount produced during 1900- 1931. Owing
pa~ tly to thIS fact and partly to a public interest in gold, the
ArIzona Bureau of Mines continues to receive numerous requests
for information regarding placers.
This Bulletin No. 160 represents a revision of the Bulletin No.
142, with addition of data from the U. S. Bureau of Mines Min­erals
Yearbooks and material accumulated by the Arizona Bureau
of Mines.
T. G. CHAPMAN
PREFACE TO BULLETIN NO. 142
The first publication of the Arizona Bureau of Mines on Ari­zona
Gold Placers was written by M. A. Allen and appeared in
1922 as Bulletin 118. It was mainly a compilation of data already
in print, but scattered and difficult to find. The stock of this
bulletin was exhausted in four years. Eldred D. Wilson, Geologist
with the Bureau, was then commissioned to rewrite the bulletin,
adding what new data could be obtained. Assisted by W. R.
Hoffman in the field and further aided by the advice and sugges­tions
of Carl Lausen, then Geologist with the Bureau, Mr. Wilson
completed his work in the summer of 1927, and a large edition
was published at once as Bulletin 124. Conditions with which
everyone is familiar developed within two or three years, and so
much interest was shown in gold that the demand for this bulle­tin
was extremely heavy, and the supply was exhausted before
June of last year. A new and greatly enlarged bulletin, No. 132,
was prepared at that time, and, although five thousand copies
were printed, they have all been distributed.
The present bulletin does not differ radically from No. 132, but
many parts of that bulletin have been rewritten and an attempt
has been made to bring the information obtained therein up to
date. Eldred D. Wilson made the field investigations required to
secure this new data, and at least a dozen additional districts are
described in the present bulletin.
Part II has been presented by G. R. Fansett to thousands of
people who have attended short courses for gold prospectors,
which he has conducted in centers of population all over the State
during the past year or two, and experience has shown that the
information conveyed is very useful, especially to inexperienced
persons.
With the exception of very recent discoveries, in spite of dili­gent
efforts to gather all the information available, the descrip­tions
of Arizona placer fields are incomplete and otherwise un­satisfactory.
It could, however, hardly be otherwise. The pioneer
prospectors and miners were too busy overcoming obstacles,
struggling against hardships and celebrating occasional periods
of good fortune to write about their experiences, even if able to
do so. Few authentic records of most of the earlier camps exist.
Available statistics are often far from reliable, and good judg­ment
is required to separate the true from the' false.
Anyone who secures a copy of this bulletin with the idea of
obtaining therefrom such data as will enable him to engage
profitably in placer mining in Arizona should remember that
gold placers are usually the first deposits found and exhausted
in every region. Prospecting for placer gold is not expensive,
and a deposit once found can be worked with little capital unless
dredging is necessary. Even hydraulic operations ( which are not
described in this bulletin because it is doubtful if any deposits
that can be worked satisfactorily in this way exist where the
~ equisite water is ~ vailable) do not ordinarily require the expend­Iture
of a! ly consIderable sum for equipment unless the water
must ~ e pIped or flumed long distances. Because placer gold can
~ e easIly and cheaply recovered where water is available, it is not
lIkely that unworked ground of fairly good grade remains, at
least al~ ng streams which flow for several months a year. People
attemptmg to do placering in such districts must therefore
ordinarily be satisfied to work ground where the' difficu1tie~
encountered, such as the prevalence of huge boulders, were too
great or the grade of gravel was too low to attract the old- timers.
Hundreds of people are, however, trying to earn wages on such
ground now.
Although there is undoubtedly much placer gold in the so­called
" desert" regions of southern Arizona the lack of water
both for placering operations and for use in the camp, is a seriou~
? rawback there, as are also the cemented conditions of the gravel
m several areas. Many types of dry- washers have been tried in
these regions, usually with very indifferent success for reasons
outlin. ed in this bulletin, and the high summer temperatures that
pre- yaII there should deter anyone from prospecting in these areas
durmg the summer months unless he is accustomed to the condi­tions
he will encounter and knows how to meet them.
Recent field investigations made by Eldred D. Wilson reveal
the fact that the average daily recovery of each experienced
pla~ er . miner ~ n the State is probably less than a dollar a day,
whIle mexperIenced persons are averaging less than 25 cents a
day.
Of cour~ e these statements m~ an that a few are doing fairly
well, a larger .!?- umber are earnmg expenses, and the majority
are not recovermg en~) Ugh . gold to buy food. Rumors that good
~ ages can be made m thIS way, therefore, should be heavily
dIscounted. A person not in robust health or one who has not
sUfficien~ funds to fin~ nce his entire trip runs a splendid chance
of starvmg to death If he tackles placer mining in Arizona. If,
however, a man in good health is out of work, has enough money
to pay camp e: x; pense. s fo~' some time, and is willing to work
hard, a prospectmg tnp WIll doubtless prove preferable to lying
around and doing nothing, but it should be taken with the full
realization that it is highly probable that little gold will be found.
Of cou. r: se, some ric~, virgin ground may be found, but the chance
of makmg such a dIscovery is small. It is this chance, however,
that has actuated all prospectors and led to the discovery of most
mineral deposits.
August 15, 1933
G. M. BUT'LER
PART I
ARIZONA GOLD PLACERS
By ELDRED D. WILSON
Geologist, Arizona Bureau of Mines
GENERAL FEATURES OF GOLD PLACERS
ORIGIN
Gold placers, or deposits such as gravel and sand which con­tain
notable concentrations of gold, all result from the slow mil­ling
and concentration processes incident to natural erosion of
pre- existing gold- bearing rocks. The origin of many gold placers
is traceable directly to auriferous veins, lodes, or replacement
deposits which, in most instances, were not of high grade.
According to Emmons, l placers are not apt to form from gold­bearing
outcrops that contain abundant manganese, iron sul­phides,
and chlorides, unless precipitating agents such as calcite,
siderite, rhodochrosite, pyrrhotite, chalcocite, nepheline, olivine,
or leucite are abundant, or unless erosion is very rapid. In other
words, the gold may be dissolved and carried below by means
of natural chlorination processes that are established when solu­tions
containing chlorides, together with sulphuric acid from the
oxidation of iron sulphides, act upon manganese dioxide; but this
process is neutralized if precipitating agents are present, and
may be ineffective if erosion is very rapid.
According to Lindgren,~ the best conditions for concentration
of gold into placers are found where deep decay of the rocks has
been followed by slight uplift. As the rocks of a region break up
under weathering, rainfall washes away most of the resultant
detritus, grinds it by striking and rubbing it together and by
dragging it along stream beds, and liberates most of the included
gold. Because gold is six or more times heavier than ordinary
rock. the liberated particles of gold will concentrate along the
bottom and come to rest where the stream gradient lessens. The
coarser particles will settle down first, and the fine and flaky gold
will be carried farther along. The best placer concentrations
probably occur in rivers of moderate ( about 30 feet per mile)
gradient, under nicely balanced conditions of erosion and deposi­tion.
Except where gravel bars may form in slower reaches, par­ticularly
within the arcs of curves, very little concentration will
take place in gorges. Such bars, through further deepening of
the channel, may be left as elevated benches.
Most of the gold in a placer generally rests on or near the
bedrock. In some instances, the coarser gold is scattered through
the lower 4 to 20 feet, or the gravel may be richest a few feet
above bedrock, but never is the richness equally distributed
IRefprences are listed numerically at end of Part 1.
Figure I.- Index map showing lGlcation of Arizona gold placer districts.
40. Catiada del Oro.
41, Clifton- Morenci.
42. GUa River.
48. Alder Canyon.
44. Qu! jotoa.
46. Papago.
46. Armai'! l08a.
47. Old Baldy.
48. Greaterville.
49. LaB Guijns or Arivaca.
50. Tyndall.
51, Harshaw.
52. Patagonia or ' Mowry.
Palmetto.
58. Nogales.
64. 01' 0 Blanco.
65. Tevistoll.
56. DOH Cabezas.
57. Pearce.
rift Glee." on.
59. Gold Gulch ( Bisbee).
60. Huachuca.
----- I-----:-~ · _-\
I · I' ,,
I · iI ,\
i · I 0' Ii - i_---,\'
! Fj I \
I" i" : r:' I ,~
!
21. Granite Creek.
22. Lynx Creek.
23. Copper BlUlln.
24. Groom Cteek.
25. Big Bug.
26. Hassayampa ( Yavapai
Couhty).
27. Model.
28. Placerlta.
29. Weaver. Rich Hill.
30. Minhehaha.
31. Black CanYon.
32. Humbug.
33. Vulture.
34. Hassayampa ( Maricopa
County).
35. San Dominga.
36. Payson.
37. GlobL~' Miaml.
: IH. Dd! lping Spring.
39. BUI · hnro~ 8a.
p--------
I,
!
-.....-....... -. -, i ..............................
1. Gila City ( Dome).
2. Laguna.
3. MugglnB.
4. Castle Dome.
6. Kofa or S. H.
6. ' rank Mountains.
7. Tri~ w.
8. Lu PIll..
9. LI1 Cholla. Oro FIno.
Middle Camp.
10. Plomosa.
11. Harquahala.
12. Chemehuevis.
13. Silver Creek.
14. Lewi:->.
16. Lookout.
16. Wri" hl Creek.
17. Willow Beach.
IH. Gold Basin.
In. King' Tut.
20. Ellft'lcn.
12
vertically. Among the best types of bedrock are compact clays,
somewhat clayey, decomposed rock, and slates or schists whose
partings form natural riffles. Smooth, hard material does not
catch or retain the gold effectively. Gold works down for some
distance into minute crevices of hard rock, for 1 to 5 feet into
pores of soft rock, and for many feet along solution cavities of
limestones.
According to Lindgren, 2 crystallized gold, which is sometimes
found in placers, indicates close proximity to the primary de­posit.
He states that there is probably no authenticated case of
crystallized gold occurring in gravels which have been transport­ed
far, and that it is difficult to believe the assumption that such
crystals are formed by secondary processes in the gravels. The
high insolubility of gold in most surface waters is demonstrated
by the fact that flake or flour gold, which commonly is in 3,000
particles per one cent's worth, may be carried by rivers of mod­erate
gradient for hundreds of miles.
The fineness, or parts of unalloyed gold per thousand, of placer
gold is generally greater than that of the vein gold of the same
district. This increase in purity, which is proportional to the
distance that the placer material has been transported and to
the decreasing size of the grains, has been shown to be due to
solution and abstraction of silver by surface waters.
DISTRIBUTION OF ARIZONA GOLD PLACERS
Owing to the presence of gold- bearing rocks in most mountain
ranges of the Southwest, gold placers which have been of
economic importance occur in every county of Arizona except
Apache, Coconino, and Navajo. As indicated on the accompanying
map ( Figure 1), the placer districts of Arizona that have been
notably worked are in the southwestern mountainous and desert
half of the State. Many placers occur in gulches that issue from
the numerous mineralized areas throughout this region.
RELATION TO PEDIMENTS
A pediment, as defined by Bryan, 3 is a more or less hilly plain,
carved on solid rock and largely without alluvial cover, at the
base of a desert mountain. The mountain slopes of a semi- arid
region tend to have a steep profile. Most of the dissected basins
or fiats that interrupt steep mountain slopes in this region prove,
upon analysis, to be related to elevated pediments.
The gold placers of Arizona, with the exception of a few that
occur within mountain valleys or gulches, are related to pedi­ments.
The gold- bearing gravels occur not only in gulches and
old channels which traverse or issue from pediments, but also,
in many cases, as mantle upon the pediment itself. This relation
may be explained as follows: As previously stated the best con­ditions
for the concentration of gold into placers are where deep
decay of the rocks has been followed by slight uplift. When re­moved
by erosion, decayed rocks tend to liberate their heavy
minerals within sufficiently short space to promote concentra-
14
Figure 2.- Ideal cross- section of mountain pediments. ( B) represents
the effect of renewed uplift and long erosion upon ( A); the pediment of
( A) has been more or less dissected, and a newer one has been formed at
the base of the mountain.
tions. Undecayed rocks, on the other hand, are broken up by
mechanical erosion which does not tend to release the heavy
minerals with sufficient uniformity to produce placer deposits.
In arid regions, mechanical erosion generally keeps ahead of
notable rock decay on steep slopes but falls behind such decay
on the the gentle slopes of pediments.
RELATION TO STREAMS
Most of the streams that have formed gold placers in Arizona
were small, intermittent, and subject to torrential floods. Hence,
placers of economic importance have been found to extend only
for a relatively short distance downstream from mineralized
pediment areas. Because of the intermittent character of the
streams, many of the placers contain part of their gold more or
less eratically distributed through a considerable thickness of
gravel. In general, however, the richest material occurs at or near
bedrock, especially where the bedrock surface forms natural
riffles or contains irregularities such as potholes.
Particularly along some of the larger streams, notable placers
occur as elevated bars which were deposited within the inner
arcs of curves.
RELATION TO GEOLOGY AND TYPES OF VEINS
The principal gold placers of Arizona are associated with areas
of crystalline rocks, such as schist, granite, and gneiss, where the
veins tend to be of the deeper- seated mesothermal and hypo­thermal
types.
15
Gold- bearing veins of the shallow- seate. d or epithermal t. ype,
which occur particularly in areas of volcamc rock, have not yIeld­ed
placers of notable economic importance.
YEARLY RAINY SEASONS OF ARIZONA
The advent of rain is of great importance to the placer miner in
Arizona. It exposes nuggets and provides temporary water for
wet methods of concentration, but it hinders the dry- washer,
whose dirt must be dry. Usually in Arizona, as in much of the
Southwest, the least rain falls in May and J~ ne . and the m? st
during July, August, and the win~ er. Often thIS ram comes WIth
local violence that fills arroyos WIth torrents.
HISTORY OF ARIZONA GOLD PLACER MINING
SUMMARY
The original discovery of placer gold in Ariz. ona probably was
made by Indians long before the advent of y. rhIte men. As early
as 1774, according to Elliot's History of Anzona ( 1884), plac~ rs
of the Quijotoa district, about 70 miles west o~ : rUCSOl:, were bemg
worked extensively by Padre Lopez, a C~ strhan pnest. In 18? 8,
according to Hamilton, 4 placers w~ r~ . dIscovered on the GIla
River, about 20 miles east of where It Joms the Colorado, by Col.
Jacob Snively. About 1862, La Paz placers, ; near the Colorado
River about 65 miles north of Yuma, were dIscovered by Capt.
Pauline Weaver. The greatly increased prospecting that followed
these discoveries soon resulted in finding of the Dome Rock,
Plomosa, San Domingo, and Yavapai County gold gravels. The
Greaterville placers became known in 1874, and by 1900 many ad­ditional
discoveries were made in various parts of the State.
Since the most important placer fields of Arizona were brought
to light prior to 1875, the most active and prosp~ rous period . for
mining them was from 1858 to about 1880. Durmg that pe~' lOd,
prospecting in portions of the region was opposed by the IndIans.
Before 1885 the cream of the placer gold had been harvested,
largely by ~ rude methods of dry- washing, sluicing, rocking, and
panning. In order to rework the gravels for . gold not rec? ve. red
by early miners, various attempts at dredgmg, hydrauhckmg,
and large- scale dry concentration have been made; most, but not
all of these afforts have been unsuccessful. In general, the placer
industry of Arizona during the last sixty years has been unsteady
and has depended upon such factors as unemployment or de­pressions.
EARLY PRODUCTION
The total production of Arizona's pl3; cers is difficult to ~ stimate,
because the major production was durmg . the early ! rontre~ days,
when no records were kept, and many mmers carned theIr gold
with them when they left the country.
16
17
The following table is based on conservative estimates which
ARIZONA PLACER PRODUCTION, 1902- 50
( Compiled from U. S. Mineral Resources and U. S. Minerals Yearbooks)
for certain districts, may be too low. '
No. of Gold Silver Total
ESTIMATED PRODUCTION OF PRINCIPAL ARIZONA GOLD
Years mines Fine oz. Value Fine oz. Value value
PLACERS PRIOR TO 1900 1902 497 $ 10,273 0 $ 0 $ 10,273
Estimated
1! 103 568 11,741 20 11 11,752
Field
Source of 1904 815 16,846 ° 0 16,846
production estimate 1905 2,064 42,663 306 186 42,849
La Paz $ 2,000,000 J. Ross Browne/) 1906 1,959 40,493 274 186 40,679
Gila City 1907 2,172 44,895 365 241 45,136
500,000 J. B. Tenney6 1908 1,497 30,943 258 137 31,080
Laguna
1909 1,386 28,649 183 95 28,744
1910 1,257 25,982 167 90 26,072
Muggins 200,000 1911 42 1,144 23,641 154 82 23,723
1912 51 2,082 43,046 388 239 43,285
1913 36 1,485 30,691 270 163 30,854
Kofa 40,000 E. L. Jones, Jr., 1914 57 1,458 30,140 241 133 30,273
U. S. G. S. Bull. 620 1915 49 1,705 35,248 309 157 35,105
1916 23 691 14,281 171 113 14,394
Castle Dome 100,000 J. B. Tenney6 1917 32 833 17,214 227 187 17,401
1918 13 205 4,234 33 33 4,267
La Cholla
1919 15 227 4,694 36 40 4,734
Middle Camp } 1920 8 221 4,567 15 16 4,583
500,000
1921 37 606 12,524 90 90 12,614
Oro Fino 1922 33 580 11,981 113 113 12,094
Plomosa 1923 24 428 8,854 72 59 8,913
1924 9 152 3,139 27 18 3,157
Weaver }
1925 18 206 4,267 24 17 4,284
Rich Hill 2,000,000 J. B. Tenney6
1926 21 339 7,007 56 35 7,042
1927 15 303 6,257 43 24 6,281
1928 22 310 6,400 46 27 6,427
Lynx Creek W. Lindgren, 1929 22 273 5,652 42 22 5,674
1,000,000 1930 41 632 13,057 85 33 13,090
U. S. G. S. Bull. 782 1931 68 1,069 22,103 157 45 22,148
Hassayampa
1932 179 3,480 71,933 454 128 72,061
) 1933 179 5,130 131,126 603 211 131,337
Big Bug 1934 867 6,982 244,030 1,038 671 244,701
Groom Creek 1,000,000 J. B. Tenney6 1935 1,197 5,157 180,495 832 598 181,093
Minnehaha 1936 787 6,488 227,066 890 689 227,755
1937 376 4,399 153,965 649 502 154,467
1938 329 4,985 174,475 628 406 174,881
Greaterville 700,000 J. B. Tenney6
1939 142 6,409 224,315 691 468 224,783
1940 276 6.241 218,435 1,108 788 219,223
Quijotoa 250,000 J. B. Tenney6
1941 184 11,931 417,585 2,205 1,568 419,153
1942 163 2,836 99,260 398 283 99,543
1943 19 319 11,165 14 10 11,175
PRODUCTION AFTER 1900
1944 17 242 8,470 90 64 8,534
1945 18 540 18,900 45 32 18,932
As shown in th~ following table, the output reported from Ari-
1946 33 398 13,930 62 50 13,980
1947 30 314 10,990 21 19 11,009
zona place~ s durmg 1902- 50 amounted to 94,560 ounces of gold 1948 39 838 29,330 136 123 29,453
together WIth 14,099 ounces of combined silver valued at $ 2830- 1949 32 565 19,775 63 57 19,832
956. Of this yalue, almost. three- fourths was p; oduced during th~ 1950 24 142 4,970 4,970
~ en- year perIod, 1933~~ 2, m large part by mechanized operations 1902- 31 27,164 $ 561,482 4,172 $ 2,592 $ 564,074
III the Lynx Creek, BIg Bug, and Quartzsite areas. 1932- 50 67,396 $ 2,260,215 9,927 $ 6,667 $ 2,266,882
. For all of the producing counties except Santa Cruz Pima and 1902- 50 94,560 $ 2,821,697 14,099 $ 9,259 $ 2,830,956
PIllal, the ~) Utput in ounces of placer gold was c~ nside; ably
greater durmg 1932- 49 than during 1902- 31. Production figures for 1951- 1959 are given in the Appendix, Page 120.
18
YUMA COUNTY
DISTRICTS
The noted gold- placer districts of Yuma County include the
Gila City, Laguna, Muggins, Castle Dome, Kofa ( S. H.), Tank,
Trigo, La Paz, Plomosa ( Plomosa, La Cholla, Middle Camp, Oro
Fino), and Harquahala. Their general locations are indicated on
Figure 1. Additional small production has been reported from
the Fortuna, Sonora, Mohawk, and Ellsworth areas.
The Yuma County districts are in one of the most arid portions
of the Southwest, with but little water outside of the Colorado
and dila rivers. The climate is uncomfortable for placer mining
during summer, but very enjoyable in winter. According to the
U. S. Weather Bureau, Quartzsite, which is near the Plomosa, La
Paz, and Dome Rock placers at an elevation of 800 feet above sea
level, has a mean annual rainfall of 6.53 inches, a mean annual
temperature of 69.6 degrees, a maximum temperature of 119 de­grees,
and a minimum of 9 degrees above zero on record. Yuma,
which is about 20 miles from the Laguna and Gila City placers at
an elevation of 141 feet, has a mean annual rainfall of 3.13 inches,
a mean annual temperature of 71.7 degrees, a maximum tempera­ture
of 118 degrees, and a minimum of 22 degrees above zero.
PRODUCTION
The yield from gold placers in Yuma County prior to 1900, as
estimated on a previous page, was perhaps $ 3,340, OOq. The re­corded
output amounted to $ 140,200 for 1905- 31 and $ 341,143 for
1932- 49, or a total of $ 481,143 for 1905- 49.
GILA CITY OR DOME PLACERS
Situation and accessibility: The Gila City placers, at the
northern end of the Gila Mountains, about twenty miles east of
Yuma, have been worked over an east- west length of approxi­mately
2 miles and a width of from l/ 4 to % mile. Gila City was
about 11h miles west of the present site of Dome, near the mouth
of Monitor Gulch. The Southern Pacific Railway and the old
Yuma- Gila Bend road skirt the northern margin of this placer
ground.
History: The Gila City placers became well known in 1858.
Hinton, 7 in 1878, recounted their early history as follows:
Within three months of their discovery, over a thousand men were at
work prospecting the gulches and canyons in this vicinity. The earth was
turned inside out. Enterprising men hurried to the spot with barrels of
whiskey and billiard tables. Jews came with ready- made clothing and
fancy wares; traders crowded in with wagonloads of pork and beans.
There was everything in Gila City within a few months but a church and
a jail. The diggings continued rich for four years and have been con­tinuously
worked on a smaller scale up to the present time.
FarishB states that Lieutenant Mowry found, in 1859, about 100
men and several families working the gravels at Gila City and
saw more than $ 20 washed from eight shovelfuls of dirt. He was
told that from $ 30 to $ 125 per day was recovered by each worker.
Although the cream of their production was skimmed before
1865, these placers have been worked more or less e: rery year
down to the present time, and all the known productIve gravel
areas have been dug over at least once.
So far, this gold has been commercially recoverable only by
dry washing or by panning of dry- washer concentrates at the
river. Many plans have been made for large- scale recovery of
the gold, but few of them ever passed the experiment. al stage.
One such enterprise, attempted in 1870, has been mentlOned by
RaymondU as follows: " At Gila City a San Francisco company
has during the last year erected works to pump water fro~ t~ e
Gila up into a large reservoir on top of the highest foot- hIlls m
order to work the placers of the vicinity by hydraulic power.
They use a 9- inch pipe through which they pump the wat~ r."
Numerous gold- saving machines, large and small, have been tned
out here but most of them were of inadequate design. The re­mains
of one ponderous screw- trommel device, brought here
scores of years ago, are still visible.
During part of 1931, G. H. Mears attempted small- scale. hy­draulicking
operations in Monitor Gulch. Water was obtamed
from a shallow well near the railway and pumped through about
% mile of small pipe. .
During the cool portion of the 1932- 33 season, approxImately
twenty- five men, mostly transients, were ~ onducti: r: g dry placer
operations in the Gila City area. The dally earnmgs per man
ranged from a few cents ul? to ~ enerally less ~ han $ 1.
The production of the GIla CIty placers prlOr to 1900 h~ s been
roughly estimated by J. B. TenneyG at $ 500,000, ~ ost of whICh v.: as
made prior to 1865. Their annual output durmg the seventIes
amounted to a few thousand dollars. u Their recorded yield for
the period 1934- 49 was valued at $ i3,828.
Topography: The Fortuna and Laguna topogl'aphic sheets, ~ s­sued
by the U. S. Geological Survey in 1929, in~ lude the q- Ila
City placers. Opposite the northern end of the GIla Mountams,
the Gila River bottom lands lie about 165 feet above sea level
and are bordered on the south by a gently northward- sloping,
dissected bench that rises abruptly from 35 to 300 feet higher.
From this bench, which is from 1J4 to 1 mile wide, the main mass
of the Gila Mountains rises steeply. Numerous canyon systems,
originating in the mountains, have cut steep, northward- trending
gulches, from 35 to 150 feet deep, in this b~ nch. .
Local geology: Faulted against the schISt of the mam moun­tain
mass is the series of probable Tertiary sedimentary rocks
that constitute the bedrock of the bench and of the placer de­posits.
These beds consist of well- stratified, weakly consoli~ ate~,
locally mud- cracked clay, marl, arkose, and sands~ one. The~ r
color is pale gray, buff, light green, or red, and theIr textur~ IS
generally fine grained, even to the very base of the mountams.
This consistently fine- grained character indicates that they were
deposited when no high mountains were very near, and the well-
20
developed, locally mud- cracked strata point to deposition in shal­low
water bodies of considerable size.
More or less faulting and tilting are evident throughout this
forplation. In the road and railway cuts about 21fz miles north
of Blaisdell, the beds strike N. 80 degrees E. and dip 25 degrees
SE. The age of the sediments is regarded as probably Tertiary,
although they are not as thoroughly cemented as the Tertiary
sediments east of Wellton. 3
After tilting, these beds were beveled to a pediment. Overlying
this pediment and capping the smooth- topped spurs of the dis­sected
bench is a mantle of gravel, up to 15 feet thick. This man­tle
extends across the fault that separates the Tertiary (?) sedi­ments
from the schist, and continues, as narrowing terraces, for
some distance headward into the canyons of the main mountain
mass. Most of the material in these gravels appears to represent
outwash from the Gila Mountains, but part of it is residual from
erosion of the Tertiary (?) beds. Bryana interprets the outwash
as having been deposited when the Gila River bed stood about
75 feet above its present level. The age of the gravels is regarded
at Quaternary.
The gulches that dissect this terrace are floored by gravel, sand
and silt that are partly of local origin but mostly have been swept
down by flood- waters from the mountains. At the edge of the
mountains this material contains subangular to rounded boulders
as much as 2 feet in diameter, but, northward, it becomes pro­gressively
finer.
Gold- bearing groavels: The Quaternary outwashed material
constitutes the gold- bearing gravels of the Gila City placers, and
the pediment carved on the underlying Tertiary (?) sediments
forms their bedrock. Most of the gold was found at or near bed­rock
in gulches, but a considerable amount was recovered from
benches. Practically all the gulches and benches from % mile
east to 3 miles west of Dome carry some gold, but Monitor Gulch,
1% miles west of Dome, was the scene of the most active mining.
Northward from a point not far south of the railway, the bed­rock
is reported to extend under the water table. Depths of more
than 15 feet to bedrock have not appeared to be profitable for
mining.
The gold not yet mined from these gravels is distributed in
rather spotty fashion. In 1926, Messrs. Neal and Morgan found
an $ 88 nugget on one of the benches near Monitor Gulch. They
found the gravel to run about 50 cents per cubic yard in a few
cuts, but 10 cents or less in many places. The fineness of this
gold was about $ 19 per ounce. Ill About half of the nuggets were
larger than match heads, and a fourth of them were from $ 3 to
$ 6 in value. Almost all of the gold particles were rough, and the
$ 88 nugget contained some white quartz.
Origin: The gold of the Gila City placers probably came from
various gold- bearing quartz veins in the northern end of the Gila
Mountains. As no high- grade veins have yet been found there, the
negative conclusion that many pockety or smal~ low- grad. e. veins
supplied the gold seems most reasonable. Durmg. deposltlOn. of
the fine- grained Tertiary (?) sediments, the GIla Mountams
probably were marked by low relief, slow erosion, and relatively
deep rock decay. After each period of subsequent uplift, they
suffered rapid erosion, and the weathered quartz vems of the
decayed rocks readily parted with their gold. Floods in th~ young
canyon systems swept this detritus northward. droppmg out
the gold as the stream gradients lessened. Further milling of
these gold- bearing gravels by repeated floods concentrated the
gold along the bottom of the channels, on the clayey bedrock.
LAGUNA PLACERS
The Laguna or San Pablo Mountains, in ranges 21 and 22W.,
immediately north of the Gila River and the Gila Mountains, con­tain
gold placers' in their southern, southeastern, and southwest­ern
portions.
The Laguna quadrangle sheet, issued by the U. S. Geological
Survey in 1929, shows the local topography. .
Production: The total output from the Laguna placers IS un­known.
Their recorded production during 1930- 42 was valued at
$ 20,103.
McPhaul area: Considerable placer mining has been done
along the southern margin of the Laguna Mountains, fr~ m near
the Gila River to about 1% miles north of McPhaul Bridge. A
little dry- washing is still carried on. Only scanty production
records for this particular area are available. During some years,
its yield was lumped with that of Gila City.
These placers, which conform to the exposure of tilted, beveled,
Tertiary (?) sediments that constitute their bedrock, occupy an
area of approximately % square mile, limited on the north and
east by the hard rocks of the Laguna Mountains, on the south by
the Gila River bottom lands, and on the west by the high gravel
capping of the range. The Tertiary (~) strata, wh? se gener~ l
character has been described on a prevlOus page, strIke and dIp
in various directions and have been displaced by reverse faults of
northeasterly trend. Many southeastward- trending arroyos have
dissected the area. Most evidences of placer mining activity are
confined to inter- arroyo benches near the base of the overlying
gravels, but some at lower elevations and also along arroyo bot­toms
are evident.
Las Flores area: Las Flores district, in the southeastern por­tion
of the Laguna Mountains and 11/ 4 miles north of the Gila
River is near the head of an alluvium floored gulch, at an eleva­tion
of 300 to 400 feet above sea level. The erosion of several gold­bearing
quartz veins in this district has given rise to small placer
deposits. . . ..
According to Raymond, 9 placer mmmg was carned on m Las
Flores area chiefly by Mexicans and Indians, at about the time
when the Gila City placers were most active. Part of this placer
22
gold occurred in the vicinity of the Golden Queen and India
claims, and some was followed downstream to the bank of the
Gila River, A little placer mining has been done in several
gulches along the southern margin of the mountains. No record
or estimate of the amount of gold recovered is available.
Laguna Dam area: At the eastern end of Laguna Dam, about
ten miles northeast of Yuma, masses of black schist and coarse,
granitic gneiss rise steeply for 250 feet above the Colorado River.
Erosion of quartz veins in these rocks has given rise to coarse,
rusty placer gold that, in places, extends into the bed of the
Colorado River. In 1884 or 1885, an attempt was made to recover
this river- channel gold by dredging, but a flood destroyed the
dredge.
In 1907, during the construction of Laguna Dam, placer nug­gets
and a small gold- quartz vein were found at the river mar­gin
of these mountains. Considerable prospecting has been done
in several of the gulches of this area, and potholes, up to 100
feet above the river, were found to carry rather coarse gold.
This coarseness points to a local origin rather than to long trans­portation
by the Colorado River. The U. S. Mineral Resources
report from the Laguna placers a production of $ 1,457 in 1910 and
$ 1,989 in 1912. The potholes yielded most of this amount and have
made some production since then.
Similar, but most extensive, pothole placers occur on the Cali­fornia
side of the Colorado River.
During the cool portion of the 1932- 33 season, a maximum of
fifty men were conducting dry- placer operations in the McPhaul
and Las Flores areas. All of the ground was privately owned, but,
in general, no royalties were charged. The average daily earnings
per man were between 50 and 75 cents. At the same time, ap­proximately
twenty- five men were placering in the Laguna Dam
area.
MUGGINS PLACERS
The Muggins Mountains, which occupy parts of Twps. 7 and 8
S" R. 18, 19, and 20 W" contain gold placers in their southern and
central portions. These placers have been known for many years
b~ t, be, cause of being less easily accessible than the neighboring
GIla CIty area, they have not been so intensively worked.
The Wellton, Fortuna, and Laguna quadrangle sheets, issued
by the U, S, Geological Survey in 1929, show the topography of
part of the Muggins Range.
In the southern portion of the range, the major placers occur
in Burro Canyon. Minor ones are found in smaller canyons in
the vicinity of a prominent mountain that is variously known as
Klotho, Coronation, or Muggins Peak, and also at the southern
base of Long Mountain. Burro Canyon, which is accesible from
Dome by some 10 miles of unimproved road, trends southward
from Muggins Peak. Here, southward- dipping lava flows, inter­calated
with thick beds of conglomerate, form a rugged terrain,
This conglomerate, which consists mainly of coarse, subangular
pebbles of gneiss and granite, rather firmly cemented in a sandy
to clayey matrix, forms the bedrock of the placers. The gold­bearing
gravels occur principally as ancient bars several feet
above the stream channel and, to a less extent, i~ the. pre, sent
stream bed, The gold occurs as particles up to 0.15 mch m dIam­eter,
mostly concentrated at or near bedrock. It. appea. rs t~ have
been derived by erosion of the conglomerate, m whIch It was
probably present as low- grade placer material deriv: ed frOi? gold­bearing
quartz veins originally contained in the gneISS, schIst, and
granite of the range. , '
Gold placers occur in the central portIOn of the Muggms Moun­tains
in the vicinity of the headward forks of the long, north­west~
ard- trending canyon that bisects the ra~ ge. The grav. els
of this canyon, which are reported to hav: e yIelded many nch
pockets during the early days, are occaSIOnally worked ~ f~ er
heavy rains. This gold probab~ y ac: umulated. from the, dIsm­tegration
of quartz veins contamed m the adJacent schIst and
gneiss. ' f
During the cool portion of the 1932- 33 se~ son,. a maXImum 0
approximately twenty- five n~ en were workmg m the southern
Muggins placer area. The dally recovery per man was generally
less than $ 1. Practically all the water used must be hauled from
wells in the Gila Valley. During 1932, E. H. Rhodes, storekeeper
at Dome, purchased $ 2,296 worth of gO, ld w~ ich came Pl~ rtly f: om
the Muggins and partly from the GIla CIty placers. BeSIdes
this amount an unknown quantity from these areas was market­ed
elsewher~. The recorded production during 1934- 42 was valued
at $ 6,867.
CASTLE DOME PLACERS
The principal gold placers of the Castle Dome M~ untains are
east and south of the Big Eye mine, which is 31 mIles by ro~ d
northeast of Dome. The gold occurs mostly at or near bedrock m
gulches and appears to have been derived from erosion of gold-bearing
veins in the vicinity. .'
These placers were discovered in 1884" but theIr productIOn to
the end of 1907 is unknown. The U. S. Mmt report for 1~ 87 states
that the field was being worked in a crude way by MeXIcan dry­washers.
According to data and esti~ ates compiled by J. B.
Tenney, 6 their yield for the 1884- 99 penod would amount to be­tween
$ 75,000 and $ 100,000.
During 1932- 33, seldom more than two or three men w~ re
working in this placer field. Operations are hampered by scarCIty
of water. .
The recorded value of output was $ 10,247 for 1908- 25, and
$ 29,589 for 1934- 44.
KoF'A OR S. H. PLACERS
A small area of gold placers in the Kofa or S. H. Mountains of
central Yuma County, about 56 miles northeast of Yum. a,. ~ as
been described by Jones. ll A geologic sketch map of the VIcIDlty
24
Figure 3.- Preliminary geologic reconnaissance map of the Kofa or S. H.
placer area, after E. L. Jones, Jr., and N. H. Darton.
is shown in Figure 3. Of these placers Jones says:
The known placer deposits of the Kofa Mountains occur in a gulch drain­ing
westward north of the detached hills in which the King of Arizona
mine is located. These placers have been worked for many years, and the
production is reported to be about $ 40,000 in gold nuggets. At present
( 1914) the placers are being worked in a small way, and a yearly pro­duction
of several hundred dollars is reported. The gold occurs in out­wash
deposits which consist of boulders and fragments from the meta­morphic
and volcanic rocks. The gold- bearing debris is said to be from
a few feet to seventy feet deep over an area of approximately sixty
acres. The gold is coarse and occurs near bedrock. It has evidently been
derived from the disintegration of auriferous veins in the metamorphic
rocks, as it is much coarser than that contained in the North Star and
King of Arizona veins. ll
During the winter and spring of 1932- 33, eight to ten men were
working in the Kofa placer area. The average daily recovery per
man. was 75 cents or less. Production of gold during 1935- 48, as
credIted to the Kofa placers by the U. S. Minerals Yearbooks, was
valued at $ 1,650.
TANK MOUNTAINS PLACERS
Some placer gold has been mined in the Tank Mountains at
various times since the seventies, but no record of the production
is available.
Probably the earliest and most profitable activity was in the
main gulch below the Johnnie or Engresser prospect, in the north­western
portion of the range. This placer gold presumably was
derived from local gold- bearing veins. As the field was small its
richer ground was soon worked out, but during the past sev~ ral
years it occasionally produced a small amount of gold.
Some fifty years ago, active dry- washing was carried on in
shallow bench and stream gravels on the pediment near the
Puzzles, Golden Harp, Ramey, and Regal prospects, at the eastern
f{ lot of the range. The gold obtained from the Puzzles area is said
to have been coarser than that from the other localities.
0,-,- l'-- L'... J'- J..__~~ Mile 5 ",,-
KEY ..............
1 IOulwash
fITTTTTJ rI1f I i ary
lu. ll.. 1lJ andesile
l7777:: l M( 110marphic
tLLLLJ rock
~ Go/~- bearing
L----. J v tI inS
Recent production from these areas has been practically negli­gible.
TRIGO PLACERS
The Trigo placers are at the western' base of the Dome Rock
Mountains, in T. 2 N., R, 21 W., approximately 22 miles by road
from Quartzsite. The gold- bearing gravels occur in arroyo bot­toms
and in ancient bars and channels. Most of the gold is in the
form of flat grains. For many years, small- scale, intermittent
dry- washing operations have been carried on in this field, but no
record of the total production exists. Operations are greatly ham­pered
by the scarcity of water and the cemented character of
the gravels. Their output during 1936- 49 was valued at $ 3.700.
LA PAZ PLACERS
Situation and accessibility: La Paz placers are south of the
Colorado River Indian Reservation of west- central Yuma County,
along the western foot of the Dome Rock Mountains, abOl~ t 9
miles west of Quartzsite and 6 miles east of the Colorado RIVer
( Figure 4). The district is accessible by some 5 miles. of unim­proved
road that branches northward from the QuartzsIte- Blythe
highway.
Topography: The Dome Rock Mountains rise steeply to , ap­proximately
2,900 feet above sea level or more than 2,000 feet
above the adjacent plains and are extensively dissected by deep
canyons. From their western foot, a wide dissected bench slopes
gently westward to low bluffs that limit the Colorado River
bottom lands. No perennial streams flow through the placer dis­trict,
but branching arroyos drain the run- off of rain:\:, seasons to
the Colorado River. Water is hauled from QuartzSIte or from
shallow wells near the river. A scanty supply is afforded by
Gonzales Wells or by natural rock tanks, such as Goodman Tank.
History: According to former State Historian Hall, l° the pres­ence
of placer gold near the Colorado River was learned from
Indians soon after establishment of the military post at Yuma.
These Indians gave a few small nuggets of gold to a trapper,
Capt. Pauline Weaver, and about 1862, according to Browne, 5
guided Weaver and his party to the rich gravels. The party
picked up about $ 8,000 in nuggets, returned to Yuma for supplies,
and spread news of the discovery. Several hundred miners soon
rushed to the district, found the placers to be very rich, and es­tablished
the adobe town of La Paz about 2% miles from the
river. This town, which soon attained a cosmopolitan popula­tion
of over 1,500, became a station on the Overland ' I'rail from
San Bernardino to Ft. Whipple and was the County seat until
1871,12 The district flourished until about 1864 when apparent
exhaustion of the higher- grade placers and discoveries of new
diggings caused a decline in activity. In 1873, 1874, and 1876,
additions to the Colorado River Indian Reservation included much
of the placer ground and greatly restricted mining. La Paz be-
27
26
o
,..
D.
)- I '"'" [ J~ [ 3= a
z
' w" ++ • a g
I- ~ m
:':"> " ,
0 c
a Vl t
0:
) ­)-'"
"" z'' l' ­'-'
",'"
~~
~ a
oz
q
f­a
« ~~
o
z?;:~
q'"
c(~~
~:..~ ~ 5
" c . J I-a.
X
w~
q
I­'"
W
I-came
practically deserted, and the site of this once flourishing
town is now marked only by adobe ruins.
After the area was excluded from the Indian Reservation in
1910. New La Paz Gold Mining Company acquired control of
a large portion of the placer ground and made preparations for
large- scale hydraulic treatment of the gravels. Four shallow
wells were drilled in the Colorado River flood plain some 4%
miles west of the placers. Water was to be pumped from these
wells through a 12- inch pipe line to a reservoir 540 feet above
the river or 225 feet above the placers. Part of the pipe line was
installed, but from 1912 to 1915 the land was again included in
the Reservation, and the project was not completed. Several
other plans for large- scale operations have been outlined, but
none of them have been carried out.
Production: Information on the earlier production of the La
Paz placers is given by Browne,'; who quotes a letter from A.
McKay, a member of the Territorial Legislature from La Paz, as
follows:
Of the yield of these placers, anything like an approximation to the
average daily amount of what was takeJ; l out per man would only be guess
work. Hundreds of dollars per day to the man was common, and now and
again a thousand or more a day. Don Juan Ferra took one nugget from his
claim that weighed forty- seven ounces and six dollars. Another party
found a chispa weighing twenty- seven ounces. Many others found pieces
of from one to two ounces up to twenty, and yet it is contended that the
greater proportion of the larger nuggets were never shown.... It is the
opinion of those most conversant with the first working of these placers
that much of the greater proportion of the gold taken out was in nuggets
weighing from one dollar up to the size mentioned above..... As has been
said above, the gold was large and generally clear of foreign substances.
.... All that was sold or taken here went for $ 16 to $ 17 an ounce. Since
the year 1864 until the present, there have been at various times many
men at work in these placers, numbering in the winter months hundreds,
but in the summer months not exceeding 75 to 100; all seem to do sufficient­ly
well not to be willing to worl< for the wages of the country, which are
and have been for some time $ 30 to $ 65 per month and maintenance. No
inconsiderable amount comes in from these placers now weekly, and only
a few days ago 1 saw, myself, a nugget which weighed $ 40, clear and
pure from foreign substance. . . . .
Of the total amount of gold taken from these mines, 1 am at a loss to
say what it has been.... 1 have failed to find any pioneer whose opinion
is that less than $ 1,000,000 were taken from these diggings within the first
year, and in all probability as much was taken out in following years.
According to Hall, IO local gold nuggets and dust were the prin­cipal
currency, particularly for gambling, in La Paz; but a large
portion of the gold obtained by Mexican placer miners went to
Mexico.
On account of the crude methods of recovering the gold, en­tirely
by dry washing in pans or wooden " bateas," only the
coarser gold could be saved, and only extremely rich ground
would be payable. Wet methods were out of the question, for,
according to Jones, 14 water packed from La Paz to the placers
brought $ 5 a gallon during the rush period. With the introduc­tion
of dry- washer machines in the late sixties, greater quan­tities
of material could be handled and a greater percentage of
28
recovery effected, but by that time most of the richer ground
had been worked over.
During the winter of 1932- 33, from fifty to sixty men were re­ported
to be conducting small- scale, individual dry- washing op­erations
in La Paz district. The average daily recovery per man
was from 50 to 75 cents.
La Paz placers are credited with a gold output valued at
$ 14,705 for 1934- 37 and $ 805 for 1942- 49. Their production for
other recent years is not separately recorded.
Local geology: The Dome Rock Mountains in this vicinity
( Figure 4) consist largely of metamorphic rocks and granite, of
Mesozoic to early Tertiary age. For a short distance west of the foot
of the range, these rocks floor a dissected pediment and consti­tute
the bedrock of the principal placers. Westward they disap­pear
beneath extensive deposits of sand, gravel, and clay which
in turn are locally overlain by coarse outwash grav~ ls and
boulders.
Distrib~ tion. and character of the placer gravels: The placers
oC, cur mamly m Goodman Arroyo a~ d Arroyo La Paz, and in
trIbutary gulches such as Ferrar, GarcIa, and Ravenna. According
to Jones, 13
Ferrar Gulch, tributary to Arroyo La Paz, contained the richest and most
productive placers of the district. Evidences of former work are seen in
the old excavations and, ... in exposures of bedrock where the wash was
shallow.... The thickness of . the gold- bearing wash is variable, ranging
from a few fe~ t on the mountam slopes to an unknown measure in Arroyo
La Paz and m the gulch traversed by the ( old) Quartzsite- Ehrenberg
road.. Shafts have bee~ ~ unk in the wash to depths of thirty feet without
reachmg bedrock and It IS reported that in places the wash is at least sixty
feet deep. By far the greater part of the auriferous material is unworked
especially that in the lower courses of the arroyos where the wash i;
deep, F'errar Gu~ ch for mo, st of its course has been p; actically worked out.
The gold- bearIng materIal consists of sand and clay inclosing angular
rock fragments of greatl~ variable size. Tests indicate that about twenty
per cent of the wa~ h wIll pass through a quarter- inch screen, and tli'e
largest ~ oulders weIgh several hundred pounds. The material near the
s1! rface IS unassorted and is unconsolidated, being readily worked with
pIck and shovel.. That at depths of fifteen or twenty feet is consolidated
but t~ e cementmg substances readily disintegrate on exposure to air:
DepOSIts of wash below the depths of test pits may prove to be similar to
the outwash on the east slope of the Dome Rock Mountains and in the
Plomosa placers, where the material is firmly cemented with calcium car­bona~
e and requires crus1; lin~ in. order to free the gold. The ground stands
suffiCIently well to permIt smkmg of shafts without use of timber The
w~ sh is readily worked in dry- washer machines, the only requir~ ment
bemg that the ground must be dry. The gold is said to be distributed
throughout the wash, though in the early workings the richest yield was
obtained near bedrock.
No estimate could be made of the probable gold content of the wasli in
the La Pa~ ~ istrict because of la~ k of detailed data and of uncertainty
as to the lImIts of the wash, but In one area the deposit, said to contain
values of 50 to 75 cents per yard and much of it thirty feet or more deep
occupies at least 640 acres, and considerable areas extend into the small':
er gulches.
The size of the gold now recovered from the deposits of the La Paz.
district probably averages only a few cents, but as' already stated the gord
recovered from the early workings was much coarser. The gold' is rough
~ nd angular, an~ particles of iron cling to some of the nuggets. Magnetite
IS ~ lw~ ys found In the concentrates, and boulders of magnetite, the largest
welgh. Ing several pounds, are frequently found on the surface.
HeIkes14 states that the largest nugget found in this region was
valued at $ 1,150 and assayed about 870 in fineness. Most of the
gold particles or nuggets ranged in value from 5 cents to $ 10,
although $ 20 and $ 40 nuggets were not uncommon.
La Paz placers were probably derived by the erosion of many
gold- bearing veins in the Dome Rock Mountains.
PLOMOSA DISTRICT
The Plomosa placer district includes the eastern and western
margins of La Posa Plain. This plain, which separates the Plo­mosa
Mountains on the east from the Dome Rock Mountains on
the west, is approximately ten miles wide and from 1,000 to 1,300
feet in elevation. It is dissected, particularly in the marginal
portions, by many shallow arroyos tributary to its northward­flowing
axial channel, Tyson Wash. These arroyos contain no
water except for short periods after heavy rains. Most of the
water used in the western part of the district is hauled from
shallow wells at Quartzsite.
Heikes14 states: " Surrounding the post office of Quartzsite, in
the Plomosa mining district, and extending in every direction,
covering an area of about 7,500 acres, is found dry- placer ground
with values to an average depth of fifteen feet and varying from
five to fifty feet. The gold content per cubic yard is reported
to average in coarse gold from ten cents to several dollars."
The most important placer fields in the Plomosa district are
La Cholla, Oro Fino, and Middle Camp, which lie near the Dome
Rock Mountains, and the Plomosa, near the Plomosa Mountains
( Figure 4). These areas have been worked intermittently by in­dividual
dry- washers since the early sixties. Several lP. rge- scale
operations have been planned or attempted. The 1901- 31 value
of production from the Plomosa placer district is given by the
U. S. Mineral Resources as $ 44,826. During part of the winter
of 1932- 33 more than 100 men were reported to be placer mining
in this district. The recorded yield during 1934- 49 was valued
at $ 176,042.
LA CHOLLA PLACER AREA
La Cholla placers comprise an area 4 or 5 miles long and of
irregular width bordering the eastern foot of the Dome Rock
Mountains south of the Quartzsite- Blythe Highway.
Here, a gently eastward- sloping pediment or rock floor eroded
largely on tilted bluish- gray slates, borders the mountains and
extending beneath the gravels of the plain, constitutes the bed~
rock of the placers.
The gravels in general consist of an unassorted aggregate of
subangular to slightly rounded slate, schist, and quartzite frag­ments,
more or less firmly cemented with lime carbonate. They
I 30
are commonly of medium texture but range in size from fine
material to boulders 3 or 4 feet in diameter.
The gold occurs mostly at or near bedrock, but some is errat­ically
distributed throughout the gravels. Its particles are char­acteristically
angular and crystallized and range in diameter
from that of a pin point up to liB inch or more. The gold has not
been transported far and probably was derived from numerous
small gold- bearing veins in the adjacent mountains. BInd: sand
is abundant only in the shallower diggings.
During the first half of 1933, the principal activity in La Cholla
placers was on a group of three claims held by G. W. McMillen
and Guy Hendrix. On part of this ground, at the eastern foot of
a low, steep spur, many old pits, shallow shafts, and drifts pro­claim
earlier placer mining actiVity. A few hundred feet farther
east, the operators sank a shaft tha, t struck bedrock at a depth
of 84 feet, According to Mr. McMillen, lO a small pay streak was
cut at a depth of 42 feet, and rather finely divided gold was found
15 feet above bedrock. At bedrock, the shaft encountered a rich
southeastward- trending channel. When visited in June, 1933,
this channel had been followed by some 300 feet of drifts and
minor stopes, but its width and length had not been determined.
As shown by these workings, the bedrock surface slopes about
15 degrees southeastward and forms natural riffles. The richest
gold- bearing gravel occurs within a few inches of the bedrock
and is particularly concentrated in the Vicinity of reefs and un­dulations
on the bedrock surface, or where boulders are abund­ant.
In places, it contains up to an ounce or more of gold per
cubic yard. Locally, crevices in the bedrock contain placer gold
for depths of 1% to 2 feet.
Although openings in these cemented gravels required little
or no timber, the material mined did not require crushing, It was
run through a %- inch trommel screen and then conveyed to a bin
from which it was passed over a two- tier dry- washer driven by a
small gasoline engine. The tailings from this operation contained
approximately 50 cents in golq per cubic yard. Production dur­ing
the first half of 1933 amounted to about $ 6,000 in gold that
ranged from 920 to 924 fine. Five men were employed.
In June, 1933, the gravels in a secondary surface channel, a
few hundred feet north of the shaft, were being mined with a
power shovel. These gravels, reported to run 75 cents per cubic
yard, were being treated experimentally in a wet jig for which
water was hauled from a well 3% miles distant.
Production figures for La Cholla placers are not available. Ac­cording
to the U. S. Minerals Yearbooks, La Posa Development
Company during 1939 operated continuously in the area and
handled 15,033 cubic yards of gravel; this project was suspended
in early 1941.
ORO FINO PLACER AREA
The Oro Fino placers are at the eastern foot of the Dome Rock
Mountains, in the Vicinity of the Quartzsite- Blythe highway.
31
Here, tiltEd,. beveled shl atI. e alndt~~ te n~~~ s~~~ t~~:~ fa~~~ c:~ n'ER~
gravels, WhlCh ar~ re a lVe y m
much slaty materIals. t' I mined but
During the early days, the~ e placer11 : e: e ~~ ~~~ h, iduals,' Ac-
~~ r~~~~ e~~ ~~~~~~[ J~ g ~~;~ s I~ it~~~ fr~~~ l~~ r~ ps~~~ l~~~~ ~:~~~
! ina Gold Mmmg ~ m~ a~ y t W From these samples it was found
sunk every few hun re ee. f ents to ' over $ 1 per
that the gold content ranged from a :~ cThe colors ran from
cubic yard and aver~ ged ~ 8 cen~ s ~~~ ~ he gold was of about $ 19
less than 1 cent to 2 cen s, eac, $ 20 67 er ounce). Here the
per ounc~ fineness, ( laluat~ of~ a~ f u~ con; olidated rock debris,
~~ l~:~~ r:~! t ili~~~~ I: ndc~~~~ rlYingcemented gravel 18 or more
feet thick. MIDDLE CAMP PLACER AREA
The Middle Ca~ p placer area, I, U:~ Oed~' etsetlybynoarthmiolef twhiedeOraot
Fino, is 4 or 5 mIles long from ea~ Mountains Here according
theCehastehrn14fo" oRticohf tsheeamDsom0 fegRraovcel on bedrock yield' f. romthfour
ttoo tenurtI~ m, es the vaIue 0 f th'ICker 1g0ratve$ ls25a" nd in creVIces ere
halvl- eurbinegen1f9o3u2, ndtwnougcgoemtspawm? erstha$ ttempOted iarge- scale operations
in this tract. d f M'ddle Camp Placer Gold, Inc., La
On ground lease rom I. ed ut a large machine equipped
Cholla Mining Compal
! 1y, L~ d., yl p; roximately 100 feet of sluice
with a 3lh- yard drag me s ove, a r cover This machine, for
boxes, and settlinghtanlksd
which wa: er was au e ff~~: aQte~ ar~ zsite, y; perated for only a
few we~ ks. I C r oration installed a plant equipped
Amencan ~ oarhse G1d d ~ Po Cottrell tables. It was operated,
with a draglme s ave an w . f b t two weeks.
with water hauled from, Qu~\ t; s~~~ n~;~ n~~ viduals were carry­ingInonJusnme,
all1- 9s3c3a, leapdprryo- xwlmasha. meg m. the Middle Camp placers.
PLOMOSA PLACER AREA
d f La Posa Plain and the western
Placers at the eas~ rn ~ ~ e 0 bout 5 miles southeast of Quartz-foot
of the Plomosa oun aIns,. a bl old in the early sixties,
site ( Figure 4), pro~~ c:~ oc~~: I~ er: va~ atle. Bancroft, lG in 19~ 9,
but no record ? f t f h nd had been honeycombed WIth
found that portIOns 0 t e grou b made to work these
small tunnels. Various attempts h~ vean~ e~ et methods. Consid­placers
on a la. rge scalbe, both bi t y
erable productIOn has een ma e yindividual, small- scale dry-washing.
t ' h' h east of the district are about
The Plomosa Moun ams, w IC b e the plain consist
2la0r0g0elfyeeot faSbCoh~ Iest, segaralmeyteel, aonr dl~~~ e; e~~ l~ a~~ rocIes. Th~ schist,
32
which contains gold- bearing quartz veins and stringers, was
probably. the original source of the placer gold.
Accordmg to Bancroft, the placer gravels, which occur in old
drainage ch. annels leading away from the southwestern part of
the mountams, are made up of fragments of schist, granite, and
quartz, cemented by lime carbonate. This conglomerate or " ce­ment
rock" ~ anges in thickness from a few inches up to many
feet, dependmg largely on the shape and size of the former
channels, arid rests upon grayish- green, schistose bedrock.
Regarding the placers, HeikesJ. i quotes extracts from a pro­fessional
report by John A. Church as follows:
In some localities pits have been sunk to a depth of twenty thirty and
fifty feet or. more to be9s of cement which are richer than the gravel. Near
the mounta~ n the gol~ IS coarser, but the gravel is much less. Miles of the
great depOSit, extendmg westward from the mountains and from three to
fo~ r miles in width, have been cut into by deep ravines, and they afford
~ I1es of banks ten to fifteen feet high in which the upper layer of gravel
IS well exposed. From these banks, as far as investigations could be made,
saIJ; lples gave an average return value of 64 cents per cubic yard with gold
estunated at $ 18 an ounce.... There were no failures. The results lay be­tween
the extremes of 42 cents and $ 1.04 per cubic yard. The limit of the
gr~ v~ l act. ually explored was 2,400 by 1,500 feet and eight yards deep....
Wlthm thIS area bedrock was not reached at any time.
During. the winter of 1932- 33, approximately twelve men were
engaged m small- scale dry- washing operations on the Plomosa
placers. Average daily earnings per man were from 25 to 50
cents. Production dUring 1942- 49 Was reported to be valued
at $ 5,740.
HARQUAHALA PLACERS
The late L. C. Shattuck, of Bisbee, stated lO that, in 1886 and
1887, he worked a small placer in Harquahala Gulch which is in
the southwestern portion of the Harquahala Mount~ ins 8 miles
south of Salome. For a short while, Mr. Shattuck and hi~ partner
e~ ch recovered abou~ an ounc. e of ~ old per day. Although long
~ mce w? rked (: mt, t~ I~ ~ lacer IS of mterest because of occurring
m the Il? medlate VICI! 1Ity of the rich Harquahala or Bonanza
lode, whIch was not dIscovered until 1888.
MOHAVE COUNTY
DISTRICTS AND PRODUCTION
In Mohave County, gold placers have been worked in the
Chemehuevis, Silver Creek, Lewis, Lookout, Wright Creek Willow
Beach, Gold Basin, and King ' Tut ( Lost Basin) areas. The most
productive of these have been the King Tut Gold Basin and
Chemehuevis. "
The recorded yield from gold placers in the County was valued
at $ 3,442 for 1909- 31; $ 52,446 for 1932- 49; and a total of $ 55,888
for 1909- 49.
CHEMEHUEVIS PLACERS
The Chemehuevis placers of southwestern Mohave County
are in the foothills of the Chemehuevis or Mohave Mountains,
about 18 miles southeast of Topock. This area is part of the Gold
Wing mining district. Its climate is relatively dry throughout
the year and hot during summer.
In general, the gravels are angular and free from large bould­ers.
Where deep, they are cemented with lime carbonate. The
gold is fairly coarse.
During the winter of 1932- 33, a maximum of thirty men were
working at one time in the placers of the Chemehuevis Moun­tains,
but most of them left with the advent of hot weather. Ac­cording
to the late J. H. Jones, lO formerly of Topock, their gold
production amounted to about $ 1,200.
A little activity was reported in Dutch and Printer's gulches,
on the northeastern side of the range.
The Chemehuevis placers have been worked intermittently
by small- scale dry methods fot many years. Probably the most
activity has been in the Mexican or Spanish diggings, in the
vicinity of the Red Hills, at the southwestern foot of the range.
The recorded production of placer gold from the district during
1934- 43 was valued at $ 7,111; it came largely from the Chief claim.
SILVER CREEK PLACERS
Some minor gold placers occur in the valley of Silver Creek,
about 6 miles by road downstream from U. S. Highway 66 and
5 miles northwest of Oatman.
lIere, an irregular pediment of volcanic rocks is overlain by
a mantle of gravels which locally contain a little placer gold.
During the winter of 1932- 33, Gold Gulch Gravel Company
attempted to work this ground with a large centrifugal bowl
machine for which water waS piped several miles. A short run,
however, sufficed to determine that the gold present was in­sufficient
to make the project profitable.
A short distance farther southeast, a little small- scale placer
mining, chiefly sluicing in connection with assessment work, has
been carried on. According to B. White, lO one of the operators,
the gravels there are very firmly cemented with caliche and con­tain
about 100 pounds of black sand per cubic yard. This gold
is about 730 in fineness.
LEWIS PLACER
The Lewis placer is on patented property of the old Bi- Metal
gold mine, 3 miles southwest of Kingman and % mile northeast
of McConnico.
Here, a granite area about 300 feet in diame. ter has been con­siderably
mineralized with slightly auriferous pyrite. Regard­ing
the Bi- Metal deposit, Schrader10 says:
The free gold to which the deposits owe their value seems to have been
derived from a considerable thickness of overlying mineralized rock. As
this overlying rock became disintegrated and was removed by erosion,
the fine gold liberated from it gradually worked into the underlying rocks
in which it is now found. Below or outside of the oxidized zone of
mechanical concentration probably only very low- grade ore occurs. In
34
~~~:~~;~~ e~ l~~~~~~ t: ti of dr
b
ainftage j within or at the border of the area,
t bi on y ow ng water has taken place several
~ n~ i~: n~~ u~ f:~ rly ~ o: re gold, of which some of the largest nuggets
been panned. a a 0 ar each in gold value, are reported to have
During the winter of 1932- 33, Al Lewis mined and sluiced the
gravels from
17
a sma~ l draw in. this area. According to E. Ross
Householder, of Kmgman, thIS material ranged in value from
$ 1 to $ 5 per cubic yard and yielded about $ 900 in gold that was
worth $ 20.21 per ounce.
LOOKOUT PLACERS
The Lookout placers are in the Maynard mining district near
the northern ~ nd of the Hualapai Mountains, about 6' miles
~~ iit~ deast of Kmgman. Here, certain areas of shallow gulch and
1 SI ~ 7gravels contain rough, wiry placer gold. E. Ross House-
$
holder states that one dry- washer in this area obtained about
150 worth of gold during the 1932- 33 season.
WRIGHT CREEK PLACERS
Sm~ ll gold plac~ rs occur in the upper reaches and tributaries
C1. jirl1: ht Cre~ k, In the northeastern portion of the Cottonwood
I s. ntermIttent, small- scale operations have been carried on
here for the past decade, but the total production has been small.
COLORADO RIVER PLACERS
thThe sands and gravels of the Colorado River, downstream from
e. mouth of the qrand Canyon, contain finely divided gold
whIch several dredgmg and sluicing operations have attempted
to ? flover: .? ne of these enterpr~ ses is mentioned by Heikes18
as 0 thWA . The l~ rge dredge bUIlt in 1909 on Colorado River
near e ~ Izona sIde, opposite EI Dorado Canyon Nevada wa~
of. the suctIOn type .... It was built to work the ~ and bar~ and
faIle. d on firs~ test to extract the fine gold. It was subse uentl
car: Ied from ItS moorings by high water and wrecked duJrig th~
sprmg of 1910."
River- bar placers: Minor amounts of coarse gold have been
~ ecovefred by small- scale operations in elevated bars that have
een or? 1ed largely by tributary canyons.
At WIllow B. each, 65 miles from Kingman and near the
Hoover Da~ hIghway, one of these ancient bars contains the
~ andY HarrIs placer. This bar covers an area of about 250 square
eet, near the . outer bow of a curve in the Colorado River and
rbsts upon an Irregula~ surface of gneissic granite some 150 feet
bo~ rd the strealm. 1
d t
IS made up of an unassorted aggregate of
ers, gr~ ve , an. sand. The boulders, which range u to mo~~ than SIX feet m diameter, are but slightly rounded Pand
cou not h; av~ been transported far. Likewise the coar
of the gold mdIcates a local derivation. This pla~ er materi: i:~
pro~ a~ yb eroded fro~ gold- bearing rocks in the Vicinity and
was e, y way of trIbutary gulches, to the river where it ac-cumulated
in the outer portion of the nearest c » rve. Subsequent
downcutting of the river has left this bar elevated in its present
position. Some thirty- five years ago, Mr. Harris worked this
placer by tunneling on bedrock. In 1920, an unsuccessful attempt
was made to sluice the gravels with water pumped from the
river. A lessee took out about ten ounces of gold during 1931.
Black sand is abundant in this placer.
Some medium coarse placer gol< l has been recovered from a
bench near the Colorado River about 21h miles north of Pyramid
Rock.
GOLD BASIN PLACERS
Situation: The Gold Basin Placers of northwestern Mohave
County are in T. 28 and 29 N., R. 17 and 18 W., about 9 miles
south of the Colorado River. Their central portion is accessible
by about 9 miles of unimproved road that branches northward
from the Kingman- Chloride- Pierce Ferry highway at the north­ern
end of Red Lake playa, 56 miles from Kingman.
History: The first known discovery of placer gold within this
area was made in May, 1932, by W. E. Dunlop. In August of
that year, approximately 100 men were testing the field with
dry- washers. Most of them left during the winter rainy season,
but about forty were there in June, 1933. As most of these
people were transients who took part of their gold elsewhere,
any approximate estimate of the production is difficult to reach.
Experienced, industrious workers each made $ 1 or more per day,
but most of the operators averaged less than that amount. Dry­washing
here is interrupted during rainy seasons.
During the summer of 1933, a large- scale dry- treatment plant
( Plate I) was installed by S. C. Searles in Sec. 29, T. 29 N., R. 18
W. This plant, equipped with grizzley, trommel, screens, and a
battery of twelve dry- washers, had a rated capacity of 20 cubic
yards of gravel per hour.
The U. S. Minerals Yearbooks credit the Gold Basin placers
during 1934- 49 with a gold production valued at $ 14,500.
Topography and geology: Gold Basin is floored largely by a
detrital fan that slopes eastward from the White Hills to Hualapai
Wash. This fan is approximately 6 miles long from west to east
by 5 miles in maximum width. Its vegetation consists principally
of small desert shrubs and abundant Yucca or Joshua trees.
Water for all purposes is hauled chiefly from Patterson Well,
several miles away.
The gold- bearing gravels occur principally in arroyos and
gulches, between elevations of 3,300 and 2,900 feet above sea
level. They consist mainly of medium- grained, angular schist
and gneiss fragments together with a minor amount of finely
divided quartz. A small proportion of boulders, generally less
than 2 feet in diameter, is present. The placer gravels are most­ly
from 1 to 3 feet thick and rest upon a bedrock of firmly
cemented gravels. Their gold occurs partly as flour gold and
partly as angular fragments that range from 5 cents to $ 3.50 in
36 37
value. Some of the gold is attached to black schist particles.
Black sand is rather abundant.
The tests that have been made of this ground show that the
gold is erratically distributed. Certain pockety channels con­tain
thin streaks that run more than $ 1 per cubic yard, but most
of the arroyo banks probably contain less than $ 1 per cubic yard.
The cemented gravels of the bedrock are reported to carry a
little gold, but no test of them has been made.
Origin: The White Hills, which are made up of granitic, schis­tose,
and volcanic rocks, contain many argentiferous and aurifer­ous
quartz veins. 16 Erosion of such veins doubtless gave rise to
the Gold Basin placers. The occurrence of most of the gold as
angular fragments, some of which are attached to black schist
particles, indicates some such nearby source.
KING TUT PLACERS
Situation: The King Tut placers of northwestern Mohave
County are in T. 29 and 30 N., R. 17 W., about 8 miles from the
Colorado River. They are accessible from Kingman, via Chloride
and the Pierce Ferry Highway, by 72 miles of improved road.
History: So far as is known, the first discovery of placer gold
within this area was made in February, 1931, by W. E. Dunlop.
According to Charles Duncan, l° the gold production prior to
June, 1933, was incidental to sampling and amounted to about
$ 700. All of this land was privately owned, chiefly by the Duncan
ranch and by the Santa Fe Railway.
On the Robeson and Joy lease, in sec. 14, T. 30 N., R. 17 E., a
Cottrell dry concentrator with a capacity of 25 tons of gravel per
hour was being installed.
During 1934- 42, a gold production valued at $ 23,510 was credi­ted
to the Lost Basin ( King Tut) placer area.
Topography and geology: Here, a gravel- floored plain, from
3,000 to 4,000 feet above sea level, rises southwestward between
Grapevine Wash and the base of a low northward- trending ridge
locally called the Lost Basin Range. Near these mountains, the
plain is a pediment floored with schist and granite. Its vegetation
consists principally of small desert shrubs and abundant Yucca
or Joshua trees. Water for all purposes is hauled from Patter­son
Well, 5 miles distant.
The richer gold- bearing gravels, as known in June, 1933, occur
within an area some 8 miles long by an undetermined width and
are confiined mainly to the arroyo- bottoms. They consist pre­dominantly
of slabby schist pebbles, with few boulders more
than 10 inches in diameter, intermingled with abundant silt
and sand. These deposits are generally less than 2 feet thick and
rest upon caliche- cemented gravels. Their gold occurs partly as
fine material and partly as flat, rugged nuggets that are known
to range up to 1/ 16 ounce in weight. Black sand is abundantly
associated with it. Northeastward, the gold particles and the
gravels become progressively finer grained.
36
Tests of part of the field showed average values of 69 cents
per cubic yard. In Most of the testing was done with dry- washers.
A few small wet machines were tried, but the water for them WaS
found to be too costly.
According to M~. Duncan, lO the underlying cemented gravels
are also gold- bearmg, but no comprehensive test of them has
been made.
. Origin: The King Tut placers probably originated from ero­SIOn
of a group of gold- bearing quartz veins in the Lost Basin
Range. The ragg~ dn~ ss of the gold nuggets, many of which carry
attached quartz, m( hcates a local derivation.
Plate n.- Sampling operations in King Tut placers, 1960.
YAVAPAI COUNTY
INTRODUCTION
Yavapa. i County includes a region of approximately 8,150
square mIles.. Exc~ pt fa: th~ edge of the plateau along its north­eastern
margm, thIS regIOn IS characterized by north- northwest­ward-
trending mountain ranges and valleys. The largest of these
ra. nges, the Br~ dshaw, is approximately 45 miles long by 20 miles
~ lde, ~ nd att~ ms a maximum altitude of 7,971 feet. The region
IS dramed. chl~ fly by the Verde, Agua Fria, Hassayampa, and
Santa Mafla flvers, of which the lower courses are 1600- 2200
feet above sea level. In general the h~ gher ridges and valieys
~ re w. ell wooded and watered, while the slopes below 5,000 feet
m altItude . tet; d to be brushy, and the country below 3,500 feet
favors semIafld types of vegetation.
39
Placers have been worked in more than thirty districts or
areas of Yavapai County. As the boundaries of these distri. cts
are not clearly defined or limited, there has been some confUSIOn
regarding the designation of local areas among the statistics re­ported
in the U. S. Mineral Resources Volumes and U. S. Minerals
Yearbooks.
Descriptions in this bulletin include the more important dis­tricts
as well as some of the minor ones for which information
has been obtained.
EARLY HISTORY
Discoveries of gold in Yavapai County were announced by two
expeditions during 1862- 63. One of them, guided by Pauline
Weaver and including Major A. H. Peeples, located the Rich Hill
placers, while the other party, headed by Capt. Joseph R. Walker,
found placer and lode gold deposits in the Lynx Creek, Hassa­yampa,
Big Bug, Groom Creek, and Granite Creek areas. Some
fifteen or twenty years earlier both Weaver and Walker had
trapped extensively in Arizona and probably had become aware
of areas favorable for prospecting.
On May 10, 1863, the Walker party organized the Pioneer
placer mining district to include " certain portions of Oolkilsipava
River and its tributaries." 2o A month later it was extended to
the " Francisco ( Verde) River on the east, to the divide of the
river Aziamp ( Hassayampa) and Antelope Creek on the west,
and to include the Agua Fria River and its tributaries." 21 Each
placer claim was to be 300 feet long by 150 feet wide.
Prescott, originally a settlement chiefly of placer miners, be­came
the Territorial capital in 1864. .
PRODUCTION
The value of production from Yavapai County gold placers
prior to 1900 is conservatively estimated at $ 4,000,000. After 1929,
interest in these placers was greatly stimulated by the financial
depression; owing largely to mechanized methods and also to
numerous small- scale operations, their value of output rose to
$ 379,800 for the year 1941. It receded during World War II and
for 1949 was $ 15,505.
The recorded yield of gold from placers in Yavapai County
amounted to $ 241,510 for 1905- 31 and $ 1,701,728 for 1932- 49, or a
total of $ 1,943,238 for 1905- 49.
LYNX CREEK PLACERS
Physical features: The Lynx Creek placers are in central
Yavapai County, along Lynx Creek from near Walker, 7 miles
southeast of Prescott, to its junction with Agua Fria Creek, 13
miles east of Prescott.
Lynx Creek, which flows northward between foothill ridges
of the Bradshaw Mountains, and northeast and eastward through
conglomerate terraces of Lonesome Valley, has an approximate
length of 18 miles. Since it extends between elevations of about
40
.... ....
.. cg
ell
U
I.
HH
H
41
7,000 and 4,600 feet above sea level and drains a large, high
region, it receives a considerable amount of water each season
and is perennial in its upper, pine- wooded course. At Prescott,
which is about 5 miles west of the creek at an elevation of 5,320
feet above sea level, the normal annual fall of rain and snow
water is 18.52 inches, the highest temperature recorded was 105
degrees, and the lowest 12 degrees below zero. 22
Early history and production: According to former State His­torian
Hall, lo the Lynx Creek placers were discovered in 1863
by a party of California miners headed by Capt. Joe Walker. As
the news of their discovery filtered back to California, the num­ber
of placer miners on Lynx Creek increased to 200 or more.
Active work, with hand rockers, pans, and small sluices, contin­ued
along the stream fOT several years before exhaustion of the
richest gravels.
Like most placers of the Southwest, unfortunately, no records
of the early- day yield are available, but Lynx Creek is noted
as ope of the most productive gold- bearing streams in Arizona.
Raymond9 reported its 1874 production at $ 10,000, and Hamil­ton4
estimated the total prior to 1881 at $ 1,000,000. According to
A. C. Gilmore, lO of Prescott, about 100 men were working the
Lynx Creek placers prior to 1885, and some of them recovered
about $ 20 per day. W. R. Shananfelt, 1° of Prescott, stated that
one man recovered $ 3,600 in eleven days from the lower reaches
of the creek.
Dredging operations: In the late eighties, B. T. Barlow- Mas­sick
built a small dam above the present Prescott- Dewey high­way
bridge, installed a few miles of 30- inch pipe, and did some
hydraulicking, but a flood destroyed the dam. About 1900, the
Speck Company tried out an old dredge a short distance below
the bridge, but the roughness of the bedrock there prevented its
success. Later, G. S. Fitzmaurice operated this dredge farther
down the creek, but, after recovering about $ 800 worth of gold,
the dredge fell apart. A large patented gold- saving machine was
tried out nearby at about this time, but also without success.
In 1927, Lynx Creek Mining Company attempted large- scale
operations with a moveable plant consisting of an Insley exca­vator,
a Barber Green stacker, screens, and sluices.
During 1932 a California- type dredge ( Plate II.) was installed
in the lower Lynx Creek placer area, on the G. S. Fitzmaurice
property, below the dam illustrated in Plate III.
The dredge was 50 feet long by 35 feet wide by three stories
high and had a capacity of 100 cubic yards per hour. It drew 30
inches of water and normally required about 85 gallons of new
water per cubic yard of gravel treated. Approximately twenty
men were employed to conduct the operation three shifts per day.
Calari Dredging Company operated this dredge during March­July,
1933, and in sixty- one days treated 60,000 cubic yards of
gravel which yielded approximately 32 cents per cubic yard. In
June of that year, the dredging was being carried on to an ap-
42
proxi~ ate depth of 6 feet. The gravel, as mined with a 1l, 2- yard
draghne shovel, was. passed through a lO- inch grizzly, then
through a trommel wlth a 5- 16- inch screen, whence the oversize
went to a stacker, and the undersize into a sluice equipped with
400 square feet of angle- bar riffles. I
Of the total gold in the gravels, from 85 to 90 per cent was
~ xtr~ cted. It ranged in size from flour up to fragments 0.1 inch
m dlameter and was accompanied by abundant black magnetic
sand.
Subsequent dredging operations in the Lynx Creek area may
be summarized as follows:
Arizona Dredging and Power Company, latter part of 1933.
L~ n~ Cree~ Placer Mine Company, 1934- 40. With large float­mg
washmg plant and two draglines, treated 556,115 cubic
yards of gravel in 1938 and 542,815 cubic yards in 1939. Was
largest producer of placer gold in Arizona
Phoenix Lynx Creek Placers Company, 1934:
Rock Castle Placer Mines Company, fast quarter of 1939.
Handled about 12,000 cubic yards of bench gravel by means
of a dr: y- Iand. dredge equipped with four bowl- amalgamators.
Placer KlI~ g Mmes, Inc., in September 1940 took over property
and equlpment of Lynx Creek Placer Mine Company
Big Bug Dredging Company 1941. .
Minona Mining Company, 1948- 49.
Other dredges at one or two properties, 1940- 42.
. Small- scale op~ l" 8tions: Intermittent small- scale placer min­mg
~ as been ca~ rled . on in the Lynx Creek area for many years,
parbcularly durmg bmes of depression. In the spring and sum­m~
r of 1933, for example, approximately thirty men were recov­erm~
gold. by rocking and sluicing there. Most of the gravel was
obtamed m small dry. side- gulches and packed to water. In
places, trees were bein~ unrooted in order to reach pay dirt be­neath
them. A short dlstance below the Dewey highway bridge
one man : was drifting on old side- gulch channels. '
Accordmg to A. S. Konselman, lO of Prescott, who kept accurate
reco~ ds of the gold produced by these operators, the average
earnmgs per man amounted to 50 cents per day.
Production since 1900: The total value of production from
the Lynx Creek placers, including the Walker area, since 1900
~ as b~ en on the or~ er of $ 1,000,000. For the period 1914- 31, as
hsted l? the U. S. Mmer~ l Resources, it was $ 27,373. For 1933- 49,
accordmg to the. U. S. Mmerals Yearbooks, it amounted to $ 903, ­604,
most of wh~ ch was recovered prior to 1942.
Geology: In lt~ south~ rn or uI? per reaches Lynx Creek flows
across. pre- Cambnan schlst, gramte, and other intrusive rocks.
In the. northeastern portions of the area these older rocks are
overlam by conglomerate of medium- grained, fairly well- rounded
gravels, firmly cemented in sand and volcanic ash. This con­glomerate,
which constitutes the bedrock of the placers of lower
Lynx Creek, appears to be overlain on the west by late Tertiary
basalt of Bald Hill. The youngest formation consists of gravel,
sand, and boulders that occupy the bed and flood plain of Lynx
Creek. This material, which contains the placer gold, is generally
well- rounded except in the upper reaches of the stream.
From near Walker to a point about 8 miles in air 1ine down­stream,
or 2 miles below the Dewey highway bridge, the
placers occur as thin relatively narrow benches or bars. Down­stream
from that point, in the bottom of the steep- walled gulch
formed in the conglomerate fill of Lonesome Valley, the placers
attain a maximum width of over 1; 8 mile and a thickness of 8 to
24 feet. Although some gold is present throughout this thick­ness,
the richest material commonly is at the conglomerate bed­rock
and in a streak 4 feet thick about 2 feet above the bedrock.
Lindgren23 states that the average value is reported at 18
cents per cubic yard. " At Walker the placers yielded nug­gets
worth as much as $ 80, at about $ 16 an ounce. Lower Lynx
Creek produced a finer- grained gold of higher value, worth about
$ 18 an ounce. Such an enrichment in the value of the gold is
common and indicates a solution of the silver by the waters."
The gold of lower Lynx Creek ranges from finely divided ma­terial
up to $ 6-$ 8 nuggets, and is associated with considerable
hematitic and magnetitic black sand.
The placer gold of Lynx Creek apparently was derived from
disintegration of numerous gold- bearing quartz veins contained
in the pre- Cambrian rocks of the Walker area.
WEAVER AND RICH HILL PLACERS
Physical features: The Weaver and Rich Hill placers are in
southern Yavapai County, a short distance northwest of Octave
and 6 to 8 miles east of Congress Junction.
This placer area is at the southern margin of the Weaver
Mountains, which rise to more than 5,000 feet above sea level
or more than 2,000 feet above the adjacent desert plain on the
south. Rich Hill attains an elevation of 5,200 feet above sea
level between the deeply eroded canyons of Antelope Creek on
the west and Weaver Creek on the east. Since the higher por­tions
of the Weaver Mountains receive at least 18 inches of rain­fall
per year, these two south- flowing creeks often have some
water in their upper courses and are subject to torrential floods
during rainy seasons.
History and production: In the early sixties a party consisting
of Capt. Pauline Weaver, Maj. A. H. Peeples, and others, hap­pened
to camp at the base of Rich Hill, after their guide had
deserted them on the desert north of Wickenburg. A Mexican
of the party, while looking for their strayed animals, discovered
loose gold nuggets on top o'f Rich Hill. This discovery led also
to the finding of placers on Weaver and Antelope creeks.
This whole area soon became the scene of intense activity, and
in five years, according to Hall, lO produced about $ 500,000. The
loose gold underneath boulders and in crevices of rocks on Rich
Hill was easily gathered, but more effort was required to work
44
I
the ~ ouldery gravels of Weaver and Antelope creeks by panning, !
rockmg, and sluicing. As much as $ 40,000 is said to have been
taken from a certain acre, and the production of the whole area
prior to 1883 was estimated by HaJl1ilton4 at $ 1,000,000. The town
of Weaver, on Weaver Creek, flourished until about 1896 but is
now marked only by crumbling ruins.. Blake, in 1899, stated
that the score or so of men who were working these placers from
year to year were supposed to be recovering over $ 2.000 per
month.
The value of known output from the Weaver and Rich Hill
: placers since 1900 has been approximately $ 150,000, of which
$ 83,975 was recorded for the years 1905- 31, and $ 62,049 for 1934- 49.
According to the late Carl G. Barth, Jr., 10 the yield for the
year prior to June, 1933, was valued at about $ 1,800. Approxi­mately
fifty men were carrying on sluicing and rocking in this
field during the winter of 1932- 33, but their. number decreased to
eighteen with the advent of summer. Because the gravels are
mostly coarse ( Plate IV) and have been repeatedly worked, the
average daily earnings were not more than 30 cents per man.
Minor amounts of dry- washing have been carried on in the
vicinity of Oro Fino Gulch, in the · southernportion of the area.
In~ 938 th~ chief producer was Universal Placer Mining C? r­poration,
whIch operated a power . shovel and dry- concentratmg
plant at the Thunderbird property.
Geology: The Weaver Mountains are made up mainly of old
granite and schist, overlain in places by younger sediments and
lava. These mountains contain the Congress, Fool's Gulch, Octave,
Yarnell, and numerous smaller gold- bearing veins. The placer
ground covers an area of approximately 8 by 5 miles. According to
local people, the most productive portions were in the northern
half of this area and included about 10 acres on top of Rich Hill;
portions of the sides of Rich Hill; channels and benches of Weaver,
Antelope, and other washes; and gravel benches that lie between
these washes.
~ ich Hill, which rises steeply for about 2,000 feet above the
plam, consists of : ather ~ ntensely jointed granite. In places, it
IS traversed by thm, lentIcular quartz veins which carry pyrite,
galena, and gold. The top of this mountain is a hilly mesa about
~ 8 mile long by % mile wide, that evidently represents ~ n ero­~
lOnal remnant of the elevated Weaver Mountain pediment. It
Includes several acr~ s of broad, shallow b. asins and drainage
channels whose gramte floors are mantled WIth granite boulders
and very thin, rusty, sandy soil. A few angular pebbles of
quartz and of hematite are locally present. The once- abundant
occurrence of placer gold within the shallow basins and drain­age
channels is proclaimed by numerous old workings that
scoured every square foot of their surface. ( See Plate V.)
Along washes and benches below Rich Hill, the placer material
consists of iron- stained gravel and sand, up to 10 or more feet
Plate IV.- Typical gravels of Weaver Creek placers.
thick, together with abundant subangular boulders that are 2
to 6 feet in diameter ( Plate IV).
Character' of the gold: According to Heikes, 14 the fineness of
the Rich Hill and Weaver placer gold is 910. On Rich Hill, accord­ing
to Blake, 24 one nugget worth $ 450, and three worth a total of
$ 1,008. were found. C. B. Hosford, l° of Octave, stated that the
largest nugget found on upper Weaver Creek was worth $ 396,
and that two chunks of quartz contained $ 450. In the spring
of 1931, a large nugget was brought into the office of the Arizona
Bureau of Mines from the Weaver region. This nugget was
described by Heinerhan25 as follows:
The nugget is in general outline shaped somewhat like a human molar.
It measures approximately 53 mm. across the widest portion of the ' roots,'
and 47 rom. from the bottom of the ' root' to ' the crown.' Several frag­ments
of slightly iron- stained quartz remain in the center of the mass.
The total weight is 270.90 grams, and it may be calculated that the nugget
consists of 252.38 grams of metal and 18.52 grams of quartz ... worth
$ 152.62 in gold and 22.71 grams of silver worth 21 cents at date of writing.
During the 1932- 33 season, a few nuggets ranging up to more
than 3 ounces each in weight were obtained from Weaver Creek.
Two nuggets, each weighing more than 5 ounces, were found
on upper Antelope Creek.
Away from the margin of the mountains, coarse gold becomes
progressively more rare.
46
Plate V.- Top of Rich Hill in 1933.
Origin: These placers probably were derived by erosion of
many small veins within the vicinity and concentrated by local
streams. Such large, angular boulders ( Plate IV) and such gen­erally
coarse gold could not have been transported far in ancient
river channels.
COPPER BASIN PLACERS
Gener~ l features: The Copper Basin placers are north of Cop­per
BaSIn Wash, between Skull Valley and the Sierra Prieta.
They are accessible from the Santa Fe Railway at Skull Valley
and Kirkland by a few miles of road.
Here, a plain slopes southwestward from an elevation of 5,500
feet at the base of the Sierra Prieta to 4,000 feet at the junction
of Skull yalley and. Copper Basin Washes. Most of this plain is
~ oored WIth extenSIve deposits of gravel, sand, and clay, locally
mterbedded and mantled with volcanic tuffs and flows, but its
easternmost 1 to 3 miles of width is a pediment that has been
carved on granite. The whole area is dissected by many south­westward-
trending gulches which are tributary to Skull Valley
Wash. Part of Copper Basin Wash carries a small flow of water
throughout the year, but the other gulches are dry except for
occasional short periods.
The bedrock of the placers generally consists of cemented
gravels, but, in certain areas relatively far from the mountains
it is hard clay. '
The gold- bearing gravels are made up largely of granitic sand
together with various amounts of boulders and clay. Near the
mounhlins. thp. houldp. rs are rp. lativelv abund: mt and coarse but.
47
in the western part of the area, they are mostly less than one foot
in diameter and constitute a small percentage of the gravels.. The
clay content is erratically distributed, but tends to be relatively
greater towards the western part of the area, except near Copper
Basin Wash where sand predominates.
The gold- bearing gravels form a relatively thin mantle on the
ridges, but range in thickness from 3 or 4 feet up to 15 or mo~ e
feet in the gulches. They contain some gold throughout theIr
thickness but generally are richest in a thin streak at or near
bedrock. Widely distributed tests indicate that much. of the
ground within this field contains from 50 to 83 cents 111 gold
per cubic yard. .
The gold, which is from 925 to 950 fine, occurs as particles th~ t
range in size from small specks up to nuggets several ounces m
weight. In the western part of the field, nuggets worth more
than 25 cents each are rare. Near the mountains, the gold frag­ments
are characteristically wiry to angular and coarse.
Associated with the gold is abundant mag: t; e~ itic black sa~ d.
In the upper portion of Copper Basin Wash, OXIdIzed copper mm­eraIs
are commonly present. Throu~ hout the southwestern por­tion
of the field, small particles of cmnabar ( mer~ ury sulphIde)
and natural amalgam, which were doubtless . derIved from the
cinnabar veins of Copper Basin, are apparent m the placer con­centrates.
Erosion of gold- bearing veins of the Sierra Prieta, partic~ ­larly
in the pediment area, provided the gold of the Copper Basm
placers. The increase in angularity and coarseness of the gold
towards the mountains indicates a local derivation.
History and production: The Copper Basin pla~ ers, which
had been intermittently worked in a small way pnor to 1929,
began to attract renewed interest with the advent of the de­pression.
During 1932, three concerns carried on large- scale operations
in the Copper Basin placers.
In the southwestern part of the field, the ~ orback and E~ ston
and Smith companies ran separate concent~ atmgplants, equIpped
with power shovels, trommels, screen, DIester- type tables and
amalgamators, which had capacities of 350 or more yards per
eight hours. Water for these plants was pumped from shallow
wells and re- used as much as possible. The Forback & Easton
plant closed down in the fall of 1932, and was taken over by
R Cassendyke. Its production is reported to have been from
$ i2 000 to $ 15 000 worth of gold, most of which was in particles
wo~ th less th~ n 25 cents each. The Smith Company was suc­ceeded
by Gold Star Placer Company, ~ lso contr? lled. by Mr.
Cassendyke. Its plant, which was resummg operatIOns m June,
1933, is illustrated in Plate VI.
During April and May, 1932, a lessee operated a Ph- yard
power shovel and a Girand. barrel concentrator on ground in
Mexican Gulch, about 2lh mIles from Skull Valley. According
48
to Mr. Lyda, l° he recovered approximately $ 5,000 worth of gold.
Some $ 15 nuggets were found, but most of the gold ranged from
$ 3 nuggets down to particles as small as a mustard seed.
In June, 1933, Operators and Developers Company had in­stalled
in the northeastern part of Copper Basin a plant with
a rated capacity of 500 cubic yards per twenty- four hours. This
plant was equipped with a vibrating grizzly, washing trommel,
vibrating screens, sluice boxes, and Wilfley and Diester- type
tables. Water was to be pumped from the Lorna Prieta mine
shaft, about 1 mile farther south. The placer gravel was to be
mined from an adjacent gulch.
During the year prior to June, 1933, from fifty to sixty small­scale,
individual operators recovered gold mainly with rockers
( Plate XI) and small sluices in Copper Basin Wash. According
to A. S. Konselman, 10 of Prescott, the daily earnings per man
ranged from 25 cents to $ 1 and averaged about 50 cents.
The U. S. Minerals Resources credit the Copper Basin placers
with a production valued at $ 1,023 for the year 1931. The yield
for the year prior to June, 1933, as estimated by G. L. Lyda, lO
of Kirkland, amounted to about $ 31,000, of which $ 26,000 came
from large- scale operations. The output for 1949, as reported
in the U. S. Minerals Yearbooks, was valued at $ 27,972. Thus the
total production for 1931- 49 was on the order of $ 60,000.
BIG BUG PLACERS
Physical features: The Big Bug district is in south- central
Yavapai County, in the general vicinity of Big Bug Creek, Mayer,
Poland, McCabe, and Humboldt. This region includes a pedi­ment
at the northeastern foot of the Bradshaw Mountains and
extends up local gulches. Big Bug Creek generally has water
in approximately the upper half of its course.
History and production: Gold was discovered within the Big
Bug district in the late sixties, but the greatest activity in placer
mining there was during the eighties of the past century. Con­siderable
sluicing, rocking, and panning have. gone on, especially
in upper Big Bug Creek as far down as Mayer, and in Chaparral
and other gulches near McCabe. Dry- washing has been done
to some extent in drier portions of the region. No estimates of
the early production are available.
In 1926, bullion having a fineness of 0.952 was recovered by
sluicing operations of the Uncle Dudley Mining Company.
Large- scale operations were attempted during 1932 by Hum­phries
Investment Company of Denver, with a large track­mounted
power shovel, a Barber Green stacker, and sluices.
In July, 1933, Pantle Brothers began large- scale operations on
a 220- acre tract leased from Messrs. Shank and Savoy, west of
Big Bug Creek and about 3 miles northwest of Mayer. In August,
1933 they were minipg old placer and mill tailings in a gulch
near Big Bug Creek; this material was bouldery to sandy, with
but little clay, and rested upon cemented gravels. The gold oc-i'
50
curred as rather irregularly distributed, flat to round and ragged
particles which ranged up to about 50 cents each in value.
Pantle Brothers' concentrating plant was equipped with four
rubber- riffled Ainlay centrifugal bowls ( Plate VII). Fed with
a one- yard power shovel, it had a capacity of 1 cubic yard per
minute and required about 300 gallons of water per minute.
Ample water for this plant was obtained at bedrock. Produc­tion
during the first forty days of run amounted to about 45
ounces of gold. Four men were employed. Approximately 9,000
cubic yards of gravel were handled during 1933, and the gold
produced in 1934 amounted to more than $ 15,000.
Subsequent operations in the Big Bug area, as reported in
the U. S. Minerals Yearbooks, have been as follows:
In 1938 a washing plant equipped with four Ainlay bowls
worked at Hill group. Hassayampa River Mining Comp~ ny
ran a dragline dredge at Lawson group but suspended
operations late in the year.
In 1939 dry- land dredging was carried on at the Savoy and
Shanks properties, and sluicing was done at the Hill, John­son,
and Caywood properties.
During 1940 a dry- land dredge and a ' dragline dredge each
worked a few months at the Shanks and Savoy property.
Big Bug Dredging Company operated a 2%- yard dragline
dredge at the Hill property the last four months of the
year and recovered 1,100 ounces of gold.
In 1941 Arical Mines, Inc., worked a dragline floating dredge at
the Star or Lawson property. Big Bug Dredging Com­pany
continued to operate at the Hill property until in
March when it ~ oved to the Lynx Creek area.
A dragline dredge operated at the Nelson and Fitch property
in 1946. Some sluicing was carried on in the district dur­ing
1943- 49.
Small- scale operations were particularly active during 1932- 33
when, according to the late F. W. Giroux, 1° sixty or more men
were placer mining within the area, largely in the gravel benches
and side gulches of Big Bug Creek, several miles northwest of
Mayer. In this area, which had been rather intensively worked
during the past, most of the mining was done by tunnels from
which the gravel was packed to sluices, rockers, or small power­driven
concentrating machines. Efforts were handicapped by
the large proportion of coarse boulders within the gravels.
The recorded gold production from the Big Bug placers
amounted to $ 30,751 for 1910- 31 and $ 462,480 for 1934- 39, or a
total of $ 493,231 for 1910- 49.
Geology: The principal rocks of the Big Bug district are pre­Cambrian
schists, smaller amounts of granite and granodiorite,
abundant rhyolite dikes, and Tertiary basalt flows.
The placers occur in stream channels and on intervening mesas
of a roughly triangular area that extends for about 20 miles east
and northeast from the head of Big Bug Creek. The gold of the
stream placers is generally coarse. One of the largest nuggets
found in the Big Bug' region contained about $ 500 worth of gold
figured at $ 20.67 per fine ounce. In the gravel mesa between
Humboldt and Mayer, the gold, which is rather finely divided
and associated with considerable clay, amounts to about thirty
to forty cents per cubic yard.
Presumably, quartz veins within older rocks of the vicinity
provided gold for the stream placers, but the finely divided gold
of the gravel mesas between Mayer and Humboldt may have
undergone longer transportation.
HASSAYAMPA PLACERS
Introduction: Placer gold occurs along much of the Hassa­yampa
drainage system in Yavapai County. This creek rises in
the Bradshaw Mountains at an elevation of approximately 7,000
feet above sea level, a few miles south of Prescott, and crosses
the Yavapai- Maricopa County line two miles north of Wicken­burg
at an elevation of about 2,000 feet. Owing to its large
drainage area, the main creek carries torrential floods in rainy
seasons and abundant subsurface water during dry months.
History: According to local reports, the greatest period of
activity in the Hassayampa placers was from 1885 to 1890. The
failure of Walnut Grove Dam in 1880 prevented large~ scale oper­ations
that had been planned for a tract downstream from Wag­oner.
Small- scale, individual sluicing and rocking have been carried
on every year, but the total production therefrom is unknown.
During the 1932- 33 season, more than fifty men were working
the Hassayampa placers of Yavapai County. Most of this activity
was confined to the side gulches. In general, the average daily
returns amounted to about 50 cents per man.
A dragline dredge worked intermittently on the Hobbs prop­erty
during 1940- 42 and 1946.
Production from the Hassayampa placers, as listed by the U. S.
Mineral Resources and U. S. Minerals Yearbooks, amounted to
$ 3,659 for 1926- 31 and $ 61,568 for 1934- 49. In addition, the Black
Rock area was credited with an output valued at $ 2,776, the
Blue Tank area with $ 1,609, and the Wagoner area with $ 1,008,
during 1934- 49.
Geology: The principal rocks of the lower Hassayampa area of
Yavapai County are pre- Cambrian granite and schist, mantled in
many places by Tertiary gravels and lavas. The upper portion
consists of pre- Cambrian schist and granite, intruded by smaller
masses of diorite, granodiorite, and rhyolite porphyry. Pre­Cambrian
to Tertiary quartz veins within the schist and granite
provided the gold that erosion has concentrated in the placer
deposits. The gold found along the upper reaches of the creek
was generally coarse, but downstream it was progressively finer.
GROOM CREEK PLACERS
The Groom Creek placers are in south- central Yavapai County
along Groom Creek, from 4 to 6 miles south of Prescott. This
54
creek heads in the Bradshaw Mountains west of Walker at an
elevation of more than 5,000 feet above sea level and joins Hassa­yampa
Creek at a point about 5 miles in air line farther south­west
and 1,900 feet lower.
These placers were discovered in the sixties and were actively
worked during the eighties. Their total production prior to
1930, according to former State Historian Hall, lO probably has
amounted to about $ 100,000.
During the past several years, only slight activity has been
reported in the Groom Creek placer field, and only small amounts
of gold have been produced there.
Quartz veins contained within the local pre- Cambrian schist,
which has" been intruded by diorite, granodiorite, granite and
dikes of rhyolite porphyry, were the original source of the gold
of these placers.
WALNUT GROVE PLACERS
The Walnut Grove placer district, south of Kirkland Junction,
includes portions of the Placerita, French, Cherry, Blind Indian,
and Mill drainage areas.
Throughout a large part of this vicinity, the gulches have dis­sected
a northeastward- sloping pediment of general elevation
less than 5,000 feet above sea level. This pediment consists of
granite, diorite, and steeply dipping schist, locally mantled by
gravel and lava. It contains many small gold- bearing quartz
veins. Erosion of such veins probably furnished the gold of
the placers.
No estimates or records of the early production of this field
are available. In 1899, Blake24 stated that " The placers . . . at
Placerita have long been known and worked, and are regarded
as good- wages mines." According to the late A. B. Colwell, I° a
dredging project was attempted several years ago on a small area
of ground in French Gulch about 1 mile below Zonia.
When water was available during the 1932- 33 season, approxi­mately
twenty- five men were placer mining in the vicinity of
the junction of French and Placerita gulches, chiefly with rock­ers
and sluices. Their average daily earnings were about 50
cents per man. According to A. R. Evans, l° of Kirkland, the pro­duction
of this area for the year prior to June, 1933, amounted to
approximately $ 2,000. This gold was fairly coarse, with many
$ 5 and $ 10 nuggets and one $ 80 nugget. It was worth about $ 18
per ounce at the old price of gold.
At the same time, in the upper portion and side gulches of
Placerita Creek, three or four men were operating long toms
and dry- washers on shallow gravels. They each obtained from
25 to 50 cents worth of coarse gold daily.
Large- scale operations were started in June, 1933, on the Maude
Lee claims, at the junction of Placerita and French gulches, The
plant included a one- yard gasoline shovel, angle- iron riffles, and
a barrel amalgamator. Here, the gravels consist mainly of
granitic sand with some medium- coarse, flat schist boulders. A
small flow of water occurred at bedrock.
The Walnut Grove placer areas were credited during 1934- 36
with a gold production valued at $ 9,339.
MINNEHAHA PLACERS
Placer gold occurs along Minnehaha Creek, about 25 miles in
air line south of Prescott, below elevations of 5,000 feet above
sea level. Lindgren23 says:
Minnehaha Flat is a northward- trending, well. tim~ ered and. watere~
basin on the headwaters of Minnehaha Creek: ~ hlCh dlScha~ ges m~ ~ a~
sayampa River near Walnut Grove, Placer mmmg was earned on ele l~
the eighties of the last century all the way up from the ' Old Log House
to the Button Mine, also in branches coming in from the east. ~ he gold
was worth about $ 17 an ounce and was extracted by arrastres, ~ IUlces, and
dry- washers. The probable production was $ 100,000, accordmg. t? Mr.
M. A. McKay, an old- time resident of the district. The fOld is belle\' ed to
have been derived from the Fortuna lode near Lapham s place.
Placers on Oak Creek, below Fenton's ranch, yielded gold val­ued
at $ 924 during 1935- 40.
MODEL PLACERS
The Model placers comprise a small area in the vic~ nity of
Model Creek on the western side of Peeples Valley. ThIS local­ity
is accessible by some 2 or 3 miles of road whi. ch branches
westward from U. S. Highway 89 at a gate % mIle north of
Peeples Valley store. These placers have been known for m~ ny
years, since the discovery of the M~ del a~ d othe: ~ old- bearmg
veins in this vicinity, but comparatIvely ~ Itt1e mmmg of them
has been done during the present generatIOn. ,
Here a granite pediment extends, from elevatIons of 5,000
to 4 500 feet above sea level between the eastern foot of the
Wea'ver Mountains and Peeples Valley. This pediment has b~ en
dissected to shallow depths by several small eastward- trendmg
streams which carry water during only part of. the ye8: r: In pl~ ces
between these gulches, it is co? cealed by thm gramtIc detrItus
and soil which supports a thIck growth of brush and scrub
oaPk. lacer gold occurs in Model and other gulches for some d." IS-tance
upstream but the principal gold- bearing gravels bemg
worked in June: 1933, occurred in small, local. basins or ch~ nnels
on the pediment for a width of about % mIle on each SIde of
Model Creek downstream from Pawley's property. .
The placer' gravels, which consist mainly of granitic sand ~ Ith
some clay and few boulders, are generally less than ~ feet t~ lCk.
They contain a little gold throughout, but a~ e richest m a
streak 6 to 12 inches thick that rests upon gramte or cemented
granitic sand. Partial tests of this pay streak s~ owed about $ 1
in gold per cubic yard. The gold occurs as faIrly rough par­ticles
that range up to about lh ounce in weight and are reported
to be about 850 fine. It was probably derived by erosion of gold­bearing
quartz veins in the vicinity.
56
In June, 1933, approximately twelve men were engaged in
small- scale placer mining operations in this field. After stripping
off the overburden, the pay streak was carefully hand- shoveled
and swept from the bedrock and hauled to Model Creek for hand
coneentration.
BLACK CANYON PLACERS
Placer gold occurs along Black Canyon, which upstream
branches into Turkey, Poland, Bumblebee, and several other
? reeks and southward drains into the Agua Fria River. Accord­mg
to Lindgren, 28
Placers have been worked at several places in Black Canyon, particularly
belo\~ the. Howard Copper Company's property. A few years ago a Portu­gese
IS saId to have taken out $ 20,000 near the old stone cabin, one mile
bel~ w Howard. There are also small placer deposits near Turkey Creek
s~ tion, and every year more or less dry washing is done by Mexicans in
thIS locality.
The placer gravels in much of this field contain abundant coarse
boulders. The gold particles are generally flat and fairly coarse.
Black sand occurs abundantly in the gravels and adheres to the
smaller gold particles.
During the cool por~ ion of the 1932- 33 season, about twenty­fi,:
e . me~, mostly transIents, were engaged in small- scale placer
mmmg m Black Canyon, chiefly between Arrastre Creek and
Cleator, and to a small extent in American and Mexican gulches.
Most of the concentrating was done with rockers and sluices and
only a small amount with dry- washers. The average daily re­turns
were very s~ all. W. J. Martin, storekeeper at Bumblebee,
purchased approxImately $ 80 worth of gold per month and esti­mated
IO
that an equal amount was marketed elsewhere. The
largest nugget found during that time came from American Gulch
and was valued at $ 14.38.
. On a bar some 3 miles south of Bumblebee, a plant equipped
WIth a power shovel, screens, and tables was operated for a short
time during the summer of 1932.
Recorded gold production from the Black Canyon placers dur­ing
1934- 49 amounted to $ 12,758.
GRANITE CREEK PLACERS
Placer gold occurs along the upper branches and main course
of Granite Creek, which rises a few miles south of, and flows
northwar