STUDIES RELATED TO WILDERNESS

PRIMITIVE AREAS

CLEAR CREEKUPPER BIG DEER CREEK AREA,

IDAHO

rEOLOGICAL SURVEY BULLETIN 1391-C

Mineral Resources of the 

Clear Creek-Upper Big 

Deer Creek Study Area, 

Contiguous to the 

Idaho Primitive Area, 

Lemhi County, Idaho

By FRED W. CATER and DARRELL M. PINCKNEY, U.S. GEOLOGICAL 

SURVEY, and RONALD B. STOTELMEYER, U.S. BUREAU OF MINES

STUDIES RELATED TO WILDERNESS PRIMITIVE AREAS

GEOLOGICAL SURVEY BULLETIN 1391-C

An evaluation of the mineral 

potential of the area

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1975
UNITED STATES DEPARTMENT OF THE INTERIOR

GEOLOGICAL SURVEY 

V. E. McKelvey, Director

Library of Congress Cataloging in Publication Data

Cater, Frederick William, 1912-

Mineral resources of the Clear Creek-Upper Big Deer Creek study area, contiguous to the

Idaho Primitive Area, Lemhi County, Idaho. 

(Studies related to wilderness primitive areas) 

(Geological Survey Bulletin 1391-C) 

Supt.ofDocs.no.: I19.3:1391-C 

1. Mines and mineral resources Idaho Lemhi Co. 

I. Pinckney, Darrell M., joint author. II. Stotelmeyer, Ronald B., joint author.

III. Title: Mineral resources of the Clear Creek-Upper Big Deer Creek study area.

IV. Series. V. Series: United States Geological Survey Bulletin 1391-C. 

QE75.B9 no. 1391-C [TN24.I2] 557.3'08s [553'.09796'78] 75-619066

For sale by the Superintendent of Documents, U.S. Government Printing Office

Washington, D.C. 20402 

Stock Number 024-001-02702-0
STUDIES RELATED TO WILDERNESS 

PRIMITIVE AREAS

In accordance with the provisions of the Wilderness Act (Public 

Law 88-577, September 3, 1964) and the Conference Report on 

Senate bill 4, 88th Congress, the U.S. Geological Survey and the 

Bureau of Mines ar«; making mineral surveys of wilderness and 

primitive areas. Areas officially designated as "wilderness," 

"wild," or "canoe" when the act was passed were incorporated 

into the National Wilderness Preservation System. Areas classed 

as "primitive" were not included in the Wilderness System, but 

the act provides that each primitive area be studied for its suitability for incorporation into the Wilderness System. The mineral 

surveys constitute one aspect of the suitability studies. This report 

describes the results of a mineral survey in the Clear Creek-Upper 

Big Deer Creek study area, contiguous to the Idaho Primitive 

Area, Idaho.

CONTENTS

Page

Summary......................................................................................................................... Cl

Introduction.................................................................................................................... 2

Previous investigations............................................................................................ 2

Present investigations.............................................................................................. 2

Acknowledgments.................................................................................................... 4

Geology........................................................................................................................... 4

Geologic setting....................................................................................................... 4

Precambrian rocks................................................................................................... 4

Gneiss, schist, and quartzite............................................................................. 4

Yellowjacket Formation................................................................................... 5

Cretaceous rocks...................................................................................................... 5

Gneissic porphyroblastic quartz monzonite.................................................... 9

Granodiorite..................................................................................................... 9

Tertiary rocks........................................................................................................... 9

Quartz monzbnite and diorite of the Crags pluton......................................... 9

Dikes................................................................................................................. 10

Quaternary alluvial deposits .................................................................................. 10

Structure................................................................................................................... 10

Geochemical studies................................................................................................ 11

Analytical techniques and results ........................................................................... 12

Economic appraisal........................................................................................................ 13

Setting...................................................................................................................... 13

Methods of study ..................................................................................................... 16

Lode claims.............................................................................................................. 17

Placer deposits......................................................................................................... 18

Placer mining................................................................................................... 20

Sampling.......................................................................................................... 21

Gold and black sands distribution................................................................... 22

Description of placer deposits.......................................................................... 23

Garden Creek placer.................................................................................. 23

Golden Queen placer................................................................................ 24

Upper Owl Creek placer........................................................................... 24

Lower Owl Creek placer........................................................................... 26

Homestake placer...................................................................................... 27

Poverty Flat placer.................................................................................... 29

Ebeneezer placer........................................................................................ 30

Lake Creek placer...................................................................................... 31

Colson Creek placer.................................................................................. 34

Shell Creek placer ..................................................................................... 35

Golden Eagle placer.................................................................................. 36

Blue Mine.................................................................................................. 37

Bear Gulch fan.......................................................................................... 37

Clear Creek deposit................................................................................... 37

Miscellaneous placers and reconnaissance samples ................................. 39

Conclusions..................................................................................................................... 39

References cited............................................................................................................... 40

v
VI CONTENTS

ILLUSTRATIONS

Page 

FIGURE 1. Index map showing location of the study area............................................. C3

2. Generalized geologic map of the Clear CreekUpper Big Deer Creek study area................................................................ 6

3- 7. Maps showing:

3. Placer deposits in the Clear Creek-Upper

Big Deer Creek study area............................................................... 19

4. Garden Creek placer........................................................................... 23

5. Upper Owl Creek placer.................................................................... 25

6. Lower Owl Creek placer.................................................................... 27

7. Homestake placer............................................................................... 28

8. Photograph showing Homestake placer workings......................................... 30

9-14. Maps showing:

9. Poverty Flat placer............................................................................. 31

10. Ebeneezer placer................................................................................. 32

11. Lake Creek placer............................................................................... 33

12. Shell Creek placer .............................................................................. 35

13. Golden Eagle placer........................................................................... 36

14. Clear Creek deposit............................................................................ 38

TABLES

Page 

TABLE 1. Analyses of samples from the Clear Creek-Upper Big

Deer Creek study area .......................................... ....................................... C14

2. Principal gold placer deposits in the study area............................................ 20
STUDIES RELATED TO WILDERNESS PRIMITIVE AREAS

MINERAL RESOURCES OF THE CLEAR 

CREEK-UPPER BIG DEER CREEK STUDY

AREA, CONTIGUOUS TO THE IDAHO 

PRIMITIVE AREA, LEMHI COUNTY, IDAHO

By FRED W. CATER and DARRELL M. PINCKNEY, U.S. Geological 

Survey, and RONALD B. STOTELMEYER, U.S. Bureau of Mines

SUMMARY

The mineral survey of the Clear Creek-Upper Big Deer Creek area contiguous to the Idaho 

Primitive Area, Idaho, was made by the U.S. Geological Survey and the U.S. Bureau of 

Mines in 1972. The area, studied at the request of the U.S. Forest Service, consists of about 85 

square miles (220 square kilometres) in the central part of the highlands of central Idaho adjacent to the northeast corner of the Idaho Primitive Area. Although the study area is near or 

adjacent to mining districts that have produced considerable mineral wealth in past years 

and that have a potential for future production, no evidence was found that indicates the 

presence of lode deposits of valuable metals. The area does contain several deposits of placer 

gold along the Salmon River and Panther Creek but all are economically submarginal.

The study area is underlain by rocks ranging in age from Precambrian to Tertiary. The 

oldest rocks are gneiss, schist, and quartzite that crop out through the central part of the area 

from Salmon River south to Big Deer Creek. Relatively low-grade metasedimentary rocks of 

the Precambrian Yellowjacket Formation underlie a few square miles in the southern part of 

the area. They are intruded by granitic rocks of the Cretaceous Idaho batholith and the Tertiary Crags pluton. Alluvial deposits occupy the valleys of the major streams.

Appraisal of the mineral resources of the study area involved reconnaissance geologic 

mapping and sampling of rocks, stream sediments, and placers. No rocks containing anomalous quantities of valuable metals were found. The results of the stream-sediment sampling program were generally negative except for anomalous tin values in the Upper Big 

Deer Creek drainage. The area has no potential for oil, gas, or coal, and contains no evidence of sources of geothermal energy.

Since discovery of gold in the Salmon River drainage in 1866, the gravel deposits in the 

study area have been intermittently prospected or worked for gold by small-scale methods. 

The investigation indicates a potential for the development of some gold placer resources 

along the Salmon River. An estimated 12.3 million cubic yards (9.4 million cubic metres) of 

gravel is on the south side of the Salmon River and west side of Panther Creek. Average nearsurface gold values of gravel deposits are estimated to range from $0.08 to $0.61 /yd3 at a price 

of $1007troy oz (0.032 to 0.247 g/m3 ). Samples indicate values near bedrock range from about 

$0.46 to $2.60/yd3 (0.186 to 1.053 g/m3 ). Most deposits are partly covered with barren overburden. Undoubtedly, there are similar amounts of auriferous gravels on the north side of

the Salmon River.

Cl
C2 STUDIES RELATED TO WILDERNESS PRIMITIVE AREAS

INTRODUCTION

The Clear Creek-Upper Big Deer Creek study area comprises about 85 

mi2 (220 km2 ) of mountainous country along the northeast border of the 

Idaho Primitive Area in central Idaho (figs. 1 and 2). This report describes the geology and contains an evaluation of the mineral resources of 

the area.

Much of the area, particularly in the western part and along Salmon 

River, is rugged and has a local relief of more than 4,000 feet (1,200 m). 

Altitudes in the area range from about 3,000 feet (915m) on the Salmon 

River at the northwest corner of the area to nearly 9,500 feet (2,900 m) on 

an unnamed peak west of Upper Big Deer Creek. Most of the area is accessible by a system of trails which are fairly well maintained and which start 

from roads bordering the area along the Salmon River, Panther Creek, 

and the head of Big Deer Creek. Some privately owned land is held along 

the Salmon River and the lower reaches of other major streams.

PREVIOUS INVESTIGATIONS

No geologic reports dealing specifically with the Clear Creek-Upper 

Big Deer Creek area have been published, but a number of reports cover 

adjacent or nearby areas. Vhay (1948) and Canney, Hawkes, Richmond, 

and Vhay (1953) have studied the Blackbird mining district. The Idaho 

Primitive Area was studied by Cater and others (1973), and the Salmon 

River Breaks Primitive Area by Weis, Schmitt, Tuchet, and Davis (1972). 

Other nearby areas have been described by Ross (1934), Anderson (1953, 

1959), Larsen and Schmidt (1958), and Shockey (1957). Ross (1941) described briefly the ore deposits in the Blackbird and other nearby mining 

districts.

The U.S. Bureau of Mines made a field survey of the placer mining districts of Lemhi County in 1938. This report by S. H. Lorain and O. H. 

Metzger (1939) included descriptions of gold placer deposits in the study 

area. The gravel bars and placer workings on the north side of the river below the confluence of the Middle Fork were recently studied by E. T. 

Tuchek (Weis and others, 1972).

PRESENT INVESTIGATIONS

Fieldwork by the U.S. Geological Survey was done by F. W. Cater and 

D. M. Pinckney in August 1972. This work consisted of reconnaissance 

geologic mapping by foot traverses and geochemical sampling. The sampling program included collection and analyses of stream sediments and 

of both unaltered and altered rocks that might possibly be associated with 

metallization.

The U.S. Bureau of Mines conducted studies of placer deposits along 

the Salmon River and Panther Creek during the summer and fall of 1972. 

Field examinations were made by R. B. Stotelmeyer, accompanied by Ar-
I 0 A

SALMON RIVER

BREAKS PRIMITIVE

AREA

FIGURE 1. Location of Clear Creek-Upper Big Dear Creek s
C4 STUDIES RELATED TO WILDERNESS PRIMITIVE AREAS

nold Mroz. They were assisted at various times by R. D. Weldin and 10 

other individuals from the U.S. Bureau of Mines. Seismic studies of the 

gravel bars were done by Eldon C. Pattee and Steven Schmauch. Placer 

concentrates were processed by Dean C. Holt.

ACKNOWLEDGMENTS

The help and cooperation of local residents who aided in the studies, 

particularly Eller and Verla Watson at Ramshead Lodge, are appreciated.

GEOLOGY

GEOLOGIC SETTING

The Clear Creek-Upper Big Deer Creek study area is underlain chiefly 

by gneiss, schist, and quartzite (fig. 2), which may be parts of the same 

rock units that underlie much of the vast mountainous mass of central 

Idaho. Coarsely crystalline gneiss and schist and subordinate quartzite 

underlie the largest part of the area. These coarsely crystalline rocks may 

be overlain in the southern part of the area by fine-grained metasedimentary rocks of the Precambrian Yellowjacket Formation. All of the metamorphic rocks are intruded by granodiorite and quartz monzonite, partly 

of the Idaho batholith (Cretaceous), and partly of the Crags pluton (Tertiary). The youngest rocks are scattered dikes of Tertiary age.

PRECAMBRIAN ROCKS

GNEISS, SCHIST, AND QUARTZITE

A complex of gneiss, schist, and quartzite, thought to be at least in part 

of early Precambrian age, crops out along the Salmon River and extends 

as far south as Big Deer Creek. No attempt was made to map individual 

units within this complex. The gneiss is strongly differentiated into light 

and dark laminae and consists mostly of quartz, plagioclase, microcline, 

and biotite, but hornblende, garnet, and muscovite are abundant locally. 

Schist is mostly coarsely crystalline, particularly to the north, and consists largely of biotite, muscovite, plagioclase, and quartz. Some of the 

gneiss and schist contains a considerable amount of granitic and pegmatitic material, mostly as thin concordant masses. Quartzite occurs as 

thick, massive, vitreous layers and as thin, micaceous lenses. Thick, 

massive layers, which dip gently northward, form prominent ledges 

along the middle and lower reaches of Garden Creek.

The complex of ancient rocks is strongly folded. Axial planes of more 

tightly compressed folds are marked by zones of extreme distortion, and 

rodding in such zones is pervasive. Superposed on the major folds in 

many places are small-scale crossfolds ranging from a fraction of an inch 

to several feet across. The axes of these crossfolds are parallel to and trend 

down the dip of foliation.
CLEAR CREEK-UPPER BIG DEER CREEK AREA, IDAHO C5

The complex of highly folded rocks has not been dated directly. The 

contact with the Yellowjacket Formation in the upper part of the Big Deer 

Creek drainage is poorly exposed if, indeed, it is exposed at all. Possibly 

the Yellowjacket Formation is younger than the complex of gneiss and 

schist. All original sedimentary features in the complex, except gross 

compositional layering, have been destroyed by recrystallization and 

metamorphic segregation, whereas such features are abundant in the presumably younger Yellowjacket Formation. Rocks somewhat similar to 

the gneiss-and-schist complex form the basement in nearby areas in 

southwestern Montana, and some of these rocks are as much as 3.1 billion 

years old (Giletti, 1966).

YELLOWJACKET FORMATION

Within the study area the Yellowjacket Formation crops out only in a 

small area east of the headwaters of Big Deer Creek where it is well exposed along the road to Blackbird Mountain; the formation is well exposed also throughout large areas in the Idaho Primitive Area (Cater and 

others, 1973). Within the study area only dark-colored argillite, siltite, and 

impure quartzite crop out, but elsewhere the formation includes calcareous and metavolcanic rocks. Most of the rocks in the study area are 

thin bedded and fine grained, and have a distinct cleavage. Despite 

thorough recrystallization, sedimentary features such as crossbedding and 

graded bedding are preserved in many outcrops. Argillite and siltite are 

dark in color and consist of fine-grained aggregates of quartz, biotite, and 

muscovite; quartzite is light colored and contains more quartz than the 

argillite and siltite.

The thickness of the Yellowjacket is not known, but in nearby areas the 

exposed thickness must approach 10,000 feet (3,000 m) and the base is not 

exposed. Where exposed in the study area, the Yellowjacket is folded and 

crumpled, but not as much as in the Blackbird mine area a few miles to the 

east.

The Yellowjacket has long been and is still assumed to be equivalent to 

some part of the Belt Supergroup (as in Ross, 1934), a sequence of rock 

that is widespread in northern Idaho and western Montana. According to 

Ruppel (1974) the Yellowjacket is similar to and probably correlates with 

the lower part of a very thick sequence of Precambrian sedimentary rocks, 

which is extensively exposed in the northern part of the Lemhi Range and 

which Ruppel correlates with the Belt. Obradovich and Peterman (1968) 

found that the Belt Supergroup in western Montana spans the age interval from about 900 to 1,300 m.y. (million years),so the correlative Yellowjacket is of Precambrian Y age.

CRETACEOUS ROCKS

Granitoid rocks of the Idaho batholith, of Cretaceous age (Larsen and 

others, 1958), underlie much of central and northern Idaho; two masses of
C6 STUDIES RELATED TO WILDERNESS PRIMITIVE AREAS
114°30'

Base from U.S. Geological Survey 

Elk City, 1:250,000,1956

FIGURE 2. Generalized geologic map of the Clear Creek-Upper Big Deer Creek 
C8 STUDIES RELATED TO WILDERNESS PRIMITIVE AREAS

s

"<31

'c

g

tj '"2 3 §

d a

O o, 

U 1

-s:

"a

 Si

tD

«1

13

£>

0

-M . a, 

3 oJ^S £ K 1-2

J3

<U

^»-t

55

 o 

« +3

3 *

 S--S

T3 S

ss

60 S

| 8 

c« ^

M "?

^ o<'

.5 x 

 3 '

V

s t ^

2 

OHH

H

A

.s

o

 3 

o

a

^

M 

>,

a.

3 

a

2 ° .s

0

11 1

11 °

fl ^

O aj

N <-i 

C * W

O t*H -"

S ^

N

1

,?

y

o

 3

o

o

N

c 

o

M c«

3a4

>

_o

"rt

O

>, *?

U

c^1"

9i*"1

3

 §

^"

1

$*

&*

W

!§

C*3

S3 *»

3 K

O
CLEAR CREEK-UPPER BIG DEER CREEK AREA, IDAHO C9

rock believed to be related to the batholith are exposed in the study area. 

Both masses are somewhat gneissic and recrystallized, and differ in these 

characteristics from most of the batholithic rocks elsewhere. Consequently, it is conceivable that both masses are prebatholith in age. Larsen 

and Schmidt (1958, p. 11-13) consider the larger mass in the eastern part of 

the study area to be a part of the batholith. The western mass, which crops 

out on the ridge west of the upper part of Garden Creek, is much smaller 

and probably does not exceed a square mile in outcrop area.

GNEISSIC PORPHYROBLASTIC QUARTZ MONZONITE

The body of igneous rock along the eastern side of the area is a gneissic 

porphyroblastic quartz monzonite of unusual appearance. Contacts with 

the enclosing gneiss and schist are fairly sharp, and locally, apophyses of 

quartz monzonite project into the gneiss and schist. The rock is gray and 

somewhat gneissic. It contains large porphyroblasts of perthitic orthoclase, many of which exceed 4 inches (10 cm) in diameter. In much of the 

rock, porphyroblasts constitute about half the volume of the rock. The 

much finer grained matrix tends to form folia that wrap around the porphyroblasts. Some of the porphyroblasts are fairly well formed crystals, 

but others are almost spherical. The gneissic groundmass is anhedral and 

crystalloblastic. It consists of biotite, quartz, oligoclase, and perthite, with 

accessory zircon, titanite, allanite, and opaque minerals.

GRANODIORITE

The small mass of igneous rock cropping out on the ridge west of 

upper Garden Creek is gray, medium-grained biotite granodiorite with a 

distinct foliation. Its contact with gneiss and schist is sharp where observed. The rock consists of somewhat perthitic orthoclase and microcline, oligoclase, quartz, and biotite. Scattered grains of hornblende occur 

sparingly; accessory minerals are magnetite, titanite, zircon, and allanite. 

The texture is anhedral and crystalloblastic. Inasmuch as this rock is not 

in contact with the porphyroblastic quartz monzonite, their relative ages 

are unknown.

TERTIARY ROCKS

Tertiary rocks include the Crags pluton, of Eocene age, and various 

dikes, some of which may be related to the Eocene Challis Volcanics 

which underlie large areas in the Idaho Primitive Area and to the south. 

Some dikes may be considerably younger than Eocene, perhaps as young 

as Miocene.

QUARTZ MONZONITE AND DIORITE OF THE CRAGS PLUTON

The Crags pluton crops out along the southwestern edge of the study 

area and forms most of the Bighorn Crags in and adjacent to the study
CIO STUDIES RELATED TO WILDERNESS PRIMITIVE AREAS

area. The contact with older rocks is sharp. The pluton consists of medium-grained to coarsely porphyritic biotite quartz monzonite that locally grades into granodiorite. Border rocks of the pluton in places have 

porphyritic and aphanitic textures, which can be ascribed to chilling. The 

rock is light gray to cream colored where fresh and is massive, widely 

jointed, and resistant to erosion. The rocks consist of oligoclase, perthitic 

orthoclase, quartz, biotite, and minor hornblende. Opaque minerals, 

titanite, allanite, and zircon are accessory. Textures are hypidiomorphic. 

To the west in the primitive area the pluton cuts the Idaho batholith. 

Radiometric ages, determined by the potassium-argon method, of micas 

of three samples from the primitive area are 44.2 to 47.5 m.y. (R. L. 

Armstrong, written commun., 1971).

DIKES

Dikes are far less common in the study area than to the southwest in the 

primitive area, but scattered silicic and basalt dikes crop out, few of which 

were mapped because of their poor exposures. Most dikes strike north. 

The more silicic dikes range in composition from andesite to rhyolite, but 

rhyodacites are probably most common. These dikes are mostly buff, 

pink, or gray porphyries containing phenocrysts of feldspar and biotite. 

Few dikes exceed 10 feet (3 m) in thickness. Basalt dikes, some of them 

more than 100 feet (30 m) thick, crop out on the ridgetop between Gant 

Mountain and Indian Point. The basalt is dark and moderately fine 

grained. These dikes resemble Tertiary dikes that crop out southwest of 

the study area; hence, their age is probably Tertiary, also. The dikes to the 

southwest have already been described (Cater and others, 1973).

QUATERNARY ALLUVIAL DEPOSITS

Alluvial deposits, consisting of locally derived boulders and gravel, are 

present in areas too small to be shown on the geologic map (fig. 2). Above 

about 5,500 feet (1,680 m) elevation, the valleys of Clear Creek and Big 

Deer Creek were glaciated; they contain no alluvium or glacial deposits, 

and the streams flow on bedrock. Narrow strips of alluvium occur along 

Salmon River, along the lower mile of Clear Creek, and along Big Deer 

Creek near the mouths of the South Fork and Indian Creek. Elsewhere, 

alluvial deposits consist almost entirely of small fans at the mouths of 

tributary streams. Most of the material in the fans consists of coarse poorly 

sorted gravel and talus that have been transported only a short distance.

STRUCTURE

Foliation and compositional layering are parallel where observed in 

the presumably pre-Belt metamorphic rocks, which are complexly folded 

and crumpled. The axial planes of the larger folds are probably inclined 

and are marked by zones of extreme deformation and rodding. Small 

crossfolds, a fraction of an inch to several feet across, are conspicuous in
CLEAR CREEK-UPPER BIG DEER CREEK AREA, IDAHO Cl 1

most outcrops of these old rocks, and ptygmatic veins of granitic material 

are common. Because of time limitations, no attempt was made to map 

even the largest folds, but a large synform was noted trending northward 

through Dome Mountain.

The Yellowjacket Formation within the study area is structurally less 

complex than the gneisses and schists, and the beds generally dip southeast at moderate angles. However, to the east, outside the study area in the 

Blackbird mine area, the beds show extreme crumpling and folding. Both 

bedding and cleavage are visible in most outcrops; where seen together 

they tend to be parallel.

A few large faults marked by zones of highly sheared material are present near the mouth of Clear Creek and about 9 miles (14.5 km) up Clear 

Creek. A thick shear zone on the ridge west of upper Garden Creek is iron 

stained. Faults with small offsets may be present but were not recognized 

because of a lack of distinctive rock units and good exposures.

GEOCHEMICAL STUDIES

The study area is in a region that has yielded considerable mineral 

wealth and therefore may have a potential for future yield; however, no 

rocks potentially productive of fossil fuels (coal, oil, and gas) exist in the 

area, and no surface evidence of potential sources of geothermal energy is 

present. The mineral potential of the area is evaluated with the aid of geochemical studies whereby trace amounts of certain elements that constitute halos of, or erosional products from, a mineral deposit are detected 

and serve as a guide to obscure mineral concentrations. Numerous prospectors, who have combed the area for more than 100 years, could not have 

overlooked any large visible ore bodies, yet none have been found, even 

though rock types and geologic structures like those in which ore deposits 

have been found elsewhere occur throughout the area. Evidence of metallization, such as altered rocks, leached rocks that may have contained ore, 

or geochemical halos, is scarce in the study area.

Testing and appraising the area involved a search for altered or leached 

rocks and sampling to determine the presence of geochemical halos. Because of the virtual absence of altered and leached rocks, heaviest reliance 

in evaluating the mineral potential of the area was placed on stream-sediment sampling. This method provided maximum information consistent with rapid coverage, because such samples contain not only erosional detritus from upstream rock masses but also the metallic ions from 

stream waters adsorbed on silt and clay particles.

All the larger streams and their side drainages were sampled and analyzed, and, in addition, samples were collected from tributaries of Big 

Deer Creek outside the study area, most importantly from the tributary 

draining the area at the north end of the Blackbird district. This was done 

so that analytical results from the edge of a known mineralized area could 

be compared with results from areas not known to be mineralized.
C12 STUDIES RELATED TO WILDERNESS PRIMITIVE AREAS 

ANALYTICAL TECHNIQUES AND RESULTS

All samples were analyzed by semiquantitative spectrographic methods for 30 elements. In addition, the stream-sediment samples were 

analyzed chemically for copper, arsenic, cobalt, and citrate-soluble heavy 

metals. Spectrographic analyses generally corroborated the results of 

chemical analyses, but differences in results are marked for some streamsediment samples. (See table 1.) These differences occur because the 

spectrographic analyses measure the total content of the element in question, whereas the chemical methods measure the amount of the surfaceadsorbed element. Stream-sediment samples containing unusually large 

amounts of metal, determined spectrographically, indicate that mineralized rock outcrops in the drainage basin, whereas high-metal values 

determined by the citrate-soluble method may indicate metal concentrations at depth beneath the drainage basin inasmuch as some of the 

surface water once circulated as ground water.

The analytical results from samples in this study area are not strictly 

comparable with those taken in previous years from the Idaho Primitive 

Area (Cater and others, 1973). The analytic techniques have been refined, 

and detection limits for some elements have changed. The bias introduced by these techniques and detection limits, however, is not thought to 

be sufficient to preclude comparisons, although the background levels for 

citrate-soluble heavy metals and for copper by chemical test are higher for 

samples from this area than for samples from the Idaho Primitive Area.

A few samples of stream sediments, numbers 20, 21, 35, 46, 47, and 68, 

contain higher than background amounts of some metals. Samples 20 and 

21 contain some lead and citrate-soluble heavy metal, probably from the 

altered rock at the head of Lake Creek and the iron-stained shear zone on 

the ridge west of Garden Creek. Samples 46 and 47 contain some lead and 

citrate-soluble heavy metals, probably from altered parts of the Crags pluton that were noted by J. S. Vhay (written commun., 1972). The small 

amount of cobalt in sample 35 probably is related to the contact of the 

large body of porphyroblastic quartz monzonite, which is slightly altered 

in many places. Several samples from upper Big Deer Creek contain as 

much as 700 ppm (parts per million) tin; these samples may represent concentrates of heavy tin-bearing minerals from the granitic rocks, which locally contain small amounts of tin.

Sample 68 is from Indian Creek, outside the area, at the extreme northern edge of the Blackbird mining district. Water from a small prospect 

drains into the creek several hundred feet above the sample site. The entire area has been very thoroughly prospected by extensive trenches and 

cuts. The only sign of mineralization found by us was a single oxidized 

and leached vein, only a few inches wide. In spite of the sparsity of mineralization, sample 68 contained 500 ppm copper, 200 ppm cobalt, and 

200 ppm arsenic much more than any other stream-sediment sample.
CLEAR CREEK-UPPER BIG DEER CREEK AREA, IDAHO CIS

Spectrographic analyses of fresh rocks, altered rocks, and miscellaneous materials are shown in table 1. The analyses of the fresh and altered 

rocks are fairly uniform among the samples; the slight variations are consistent with variations expected in rocks of the types sampled. The two 

samples of altered rocks do not differ appreciably from the fresh rocks.

Samples 340, 341, and 342 (table 1) include a sample of oxidized material from the vein in the Blackbird district mentioned above, a secondary 

coating of malachite, and a sample from a spring deposit. The vein material is high in copper, cobalt, and arsenic, which is expectable from a vein 

at the edge of the Blackbird mining district. The chief ore minerals in the 

district are chalcopyrite (CuFeS2 ) and cobaltite (CoAsS). The coating of 

malachite is rich in copper only, and represents a very small amount of 

metal deposited by ground water. The spring deposit is mostly covered by 

a mantle of soil; it is highly calcareous and appears to be tufa, such as is 

deposited by hot springs. The tufa sample is not enriched in any valuable 

metal.

Our investigations lead us to conclude that although sizable metallic 

deposits are known adjacent to the study area, the surficial mineral resources potential within the area is low.

ECONOMIC APPRAISAL

By RONALD B. STOTELMEYER, U.S. Bureau of Mines

SETTING

The Clear Creek-Upper Big Deer Creek study area in Lemhi County is 

bounded on three sides by productive mining districts: the Mineral Hill 

district to the north, the Mackinaw (Leesburg) district to the east, and the 

Blackbird district to the south (fig. 1). Lemhi County has produced 

515,000 troy oz (16,000,000 g) of gold (Staley, 1946, p. 22) and cobalt, 

nickel, copper, molybdenum, silver, and lead. A major portion of this 

production was from the northwestern part of the county within 20 miles 

(32 km) of the study area.

The Mineral Hill district contains inactive gold lode and placer mines 

in the Owl Creek drainage. Owl Creek empties into the Salmon River near 

the upstream end of a series of auriferous gravel deposits in the study area 

(fig. 3). Gold from this drainage and other drainages upstream are the 

probable source of the placer values in the deposits examined. Lode mines 

at Shoup, which is on the Salmon River several miles upstream from the 

study area, are considered to be some of the most promising gold lode 

mines in Lemhi County.

Other sources of gold include numerous lode and placer deposits in the 

Gibbonsville district on the North Fork of the Salmon River, the 

Mackinaw (Leesburg) district, which borders the study area on the east, 

and the Blackbird district to the south. The Mackinaw district includes
C14 STUDIES RELATED TO WILDERNESS PRIMITIVE AREAS

TABLE 1. Analyses of samples from the Clear Creek-

[ppm, parts per million; CxHM, citrate-soluble heavy metals; CxCu, cold-extractable copper; number in parentheses indicates sensitivity limit of method used; L, indicates detected, but below limit of determination; N, indicates that 

the element was looked for but not found; , not determined. Also looked for and not found or present in amounts

Semi quant i tat ive spect

(percent)

Sample

16

17

18

19

20

21

22

23

2k

25

26

27

28

29

30

31

32

33

3<t

35

36

37

38

39

kO

<4l

k2

<43

<4<4

<45

kk

<47 148

<i9

50

535<i

55

56

57

58

59

60

61

62

63

6*4

65

66

67

68

69

70

71

Ti 

(.002)

0.7

1.0

.3

.3

.3

.2

.5

.2

.3

.3

1.0

1.0

.7

.3

.5

.3

.2

.2

 5

.3

.7

.05

.2

.05

.2

.2

.2

 3

.07

.1

.15

.2

.2

.15

.1

.2

.3

.15

.3

.2

.2

.3

.3

.5

.2

.3

.15

.3

.3

.5

.2

.2

.3

.2

Zn 

(200)

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

Mn 

(10)

1 ,000

1,500

300

150

200

150

300

200

200

150

1 ,500

1 ,500

1 ,000

200

200

300

300

200

500

300

700

300

700

200

500

1 ,000

500

700

150

200

700

700

600

700

150

200

500

150

500

200

200

300

150

200

150

200

150

150

300

300

150

200

150

300

V 

(10)

Stream-si

100

70

70

50

70

70

70

70

70

70

150

too

100

70

70

70

70

70

100

70

100

L

20

10

30

30

30

30

L

L

20

30

30

20

10

20

30

10

70

20

70

70

70

70

70

70

50

70

70

70

30

50

50

100

Zr 

(10)

:d i merit

300

1,000

200

200

200

200

300

200

300

300

1 ,000

300

200

200

300

150

150

200

300

150

200

200

300

200

300

300

200

300

100

200

100

300

200

300

150

100

500

500

300

200

200

100

300

300

300

500

200

300

200

300

300

300

300

70

rographic analyses

(ppm)

La 

(20)

samples

100

150

30

N

20

30

30

30

70

70

100

70

50

50

30

70

20

30

30

L

150

20

70

30

50

30

100

200

N

20

30

50

100

50

20

50

300

70

20

70

20

20

30

30

50

50

30

50

70

70

30

30

20

20

Ni 

(5)

30

10

20

10

20

15

15

20

15

15

10

15

10

7

7

10

15

15

20

30

20

5

7

5

5

7

5

5

5

L

5

L

5

L

L

5

L

L

15

5

15

30

30

20

15

20

15

30

10

20

15

10

15

20

Cu 

(5)

20

20

20

15

15

15

20

20

20

15

20

15

20

15

10

15

70

30

50

100

15

20

10

15

15

20

10

7

15

5

15

15

15

7

5

10

5

15

20

15

7

50

50

30

15

70

15

20

15

15

500

15

20

15

Pb 

(10)

30

10

N

15

150

50

15

15

N

10

15

10

10

10

10

15

10

15

15

15

15

50

10

50

70

30

70

70

20

20

50

100

50

30

15

30

15

15

20

15

10

20

N

10

10

10

10

10

10

10

N

10

N

15

B 

(10)

10

L

20

15

50

20

N

70

30

20

L

L

10

10

10

20

20

30

30

20

10

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

10

15

N

30

N

N

20

30

N

N

50

20

N

20

Y 

(5)

150

100

20

30

30

30

50

30

50

70

70

70

70

30

30

30

20

50

70

30

150

70

100

20

300

100

100

150

30

20

100

100

70

100

70

20

70

30

20

20

20

15

50

20

30

50

30

30

30

70

30

30

10

100
CLEAR CREEK-UPPER BIG DEER CREEK AREA, IDAHO C15

Upper Big Deer Creek study area, Lemhi County, Idaho

normal for type of material sampled were, Ca (.05), Mg (.02), Fe (.05), in percent, and Mn (10), Au (10), Bi (10), 

Cd (20), Nb (10), Sb (100), Sc (5), and W (50), in parts per million. Analysts: R. N. Babcock, B. Crim, C. A. 

Curtis, J. A. Domenico, R. T. Hopkins, R. W. Leinz, R. C. Miller, and D. F. Siems]

Semiquant itat

Sample Ho 

(5) (10)

Co 

(5)

ve spectrographic analyses Coot 

(ppm)

Be 

(1)

Cr Ba 

(5) (10)

Sr 

(100)

nued

Ag 

(.5)

As 

(10)

Chc

CxHM 

(.5)

mical analyses 

(ppm)

CxCu 

(.5)

As 

(10)

Stream-sediment samples--Continued

16

17 

18 

19 

20

21 

22 

23 

24 

25

26 

27 

28 

29 

30

31 

32 

33

34

35

36 

37 

38 

39 

40

41

42

43 

44 

45

46

47 

148

49

50 

53

54

55 

56 

57

58 

59 

60 

61 

62

63

64

65 

66 

67

68 

69 

70 

71

N 

N 

N 

N 

N

N 

N 

N 

N 

N

N 

N 

N 

N 

N

N 

N 

N 

N 

N

N 

N 

N 

5 

10

L 

5 

N 

7 

10

5 

L 

N 

N 

N

N 

N 

N 

N 

N

N 

N 

N 

N 

N

N 

N 

N 

N 

N

N 

N 

N 

N

N 

N 

N 

N 

N

N 

N 

N 

N 

N

N 

N 

N 

N 

N

N 

N 

N 

N 

N

N 

30 

700 

15 

20

20 

20 

300

to

10

30 

20 

20 

10

15

N 

10 

L 

N 

L

N 

N 

N 

N 

N

N 

N 

N 

N 

N

N 

N 

N 

10

15 

10 

10 

N

5

5 

15 

15 

15 

15

15 

15 

15 

10 

15

15 

15 

15 

15 

150

15 

N 

N 

N 

N

7 

N 

N 

N 

N

N 

N 

N 

N 

N

N 

N 

N 

5 

N

10 

10 

10 

10 

7

7 

15 

20 

10 

10

200 

5 

10 

15

.5 

.0 

.5 

.5 

.0

.5 

.5 

.5 

.5 

.0

.0 

.0 

.0 

.5 

.5

1.5 

2.0 

2.0 

1.5 

2.0

2.0 

20.0 

10.0 

15.0 

30.0

20.0 

15.0 

7.0 

7-0 

7.0

15-0 

20.0 

10.0 

10.0 

7-0

2.0 

3-0 

3-0 

2.0 

3.0

2.0 

3-0 

3.0 

1.0 

1.5

2.0 

1.0 

1.5 

2.0 

3.0

1.5 

1.5 

L 

1.0

70 500 

30 150 

50 200 

30 300 

70 150

30 200 

30 300 

50 200 

30 200 

50 150

20 150 

50 150 

30 200 

30 150 

30 300

50 300 

70 200 

50 150 

70 150 

50 150

70 150 

N L 

10 30 

N 20 

10 50

15 70 

L 70 

10 50 

N 30 

N 20

L 30 

10 70 

10 70 

10 70 

N 30

L 150 

L 100 

10 100 

50 150 

15 100

30 150 

50 150 

50 150 

50 150 

30 200

50 300 

30 300 

70 200 

30 150 

50 150

30 150 

30 200 

20 150 

30 150

N 

100 

L 

100 

100

150 

100 

100 

100 

100

200 

300 

200 

150 

150

150 

150 

150 

100 

150

100 

N 

N 

N 

N

N 

N 

N 

N 

N

N 

N 

N 

N 

N

100 

100 

L 

150 

100

100 

100 

150 

100 

100

150 

150 

100 

150 

150

L 

100 

L 

1,500

N 

N 

.5 

N 

.5

.5 

N 

L 

N 

N

N 

N 

N 

N 

N

N 

N 

N 

N 

N

N 

N 

L 

N 

N

N 

N 

N 

L

N

N 

N 

N 

N 

N

N 

N 

N 

N

N

N 

L 

N 

N 

N

N 

N 

N 

N 

N

N 

N 

N 

.5

...

<4

3

1 

L 

20

17

<4

3 

7

<4

5 

7 

5 

3 

3

7 

2 

3

1

<4

9 

1 

5 

5 

3

5 

14 

4 

7

l<4

17 

5 

2 

1

2 

3 

1

4

3

2 

4

<4

1

9

<4

1

<4

7

<4

17 

9 

1 

2

3

4 

4 

<4

3

5 

3 

5 

4 

1

2 

5 

1 

3 

3

10

<4

4

4

15

N 

2 

5 

3 

1

3 

3 

2 

3

2 

3 

2 

L 

3

1 

1 

N

<4 

<4

N

<4

3 

2 

3

L 

5 

7 

4 

3

90 

7

<4

5

N 

N 

L 

N 

N

N 

N 

N 

L 

L

N 

N 

N, 

L 

L

10 

N 

N 

N 

L

N 

N 

N 

N 

N

N 

N 

N 

N 

N

N 

N 

N 

N 

N

N 

N 

N 

N

N 

N 

N 

N 

N

N 

N 

N 

N 

N

20 

N 

N 

N
C16 STUDIES RELATED TO WILDERNESS PRIMITIVE AREAS

TABLE 1 Analyses of samples from the Clear

Semiquanti tative spectrographic analyses Continued

Sample ____(percent)_____ __________________________(ppm)__________________________

Ti Zn Mn V Zr La Ni Cu Pb B Y

________(.002) (200) (10) (10) (10) (20) (5) (5) (10) (10) (5)

ROCK SAMPLES 

Unaltered rocks

319

320

321

322

3214

325

326

327

328

331

335

336

337

338

339

31414

0.2 N

 3 N

 3 N

.05 N

.15 N

 3 N

.2 N

.07 N

.1 N

.2 N

.1 N

.015 N

.03 N

.07 N

.07 N

.2 N

50

500

70

L

100

150

200

20

20

200

300

200

200

20

200

100

10

50

50

L

10

70

50

L

L

20

L

L

L

L

L

20

70

100

100

30

100

100

100

50

70

100

30

70

70

30

300

50

N

30

20

N

20

20

50

20

20

30

20

20

20

20

50

30

5

N

20

5

7

20

20

5

L

10

L

L

L

L

L

5

15

5

50

L

L

L

L

L

L

L

L

L

L

L

L

10

20

L

N

N

L

L

10

10

L

L

15

20

30

10

L

L

10

L

10

L

L

L

20

15

10

L

L

L

L

L

L

L

10

30

10

L

15

20

20

L

L

20

20

70

70

L

70

20

Altered rocks

323

343

0.3 N 

.07 N

70 

50

50 

15

150 

70

20 5 

20 5

L N 

20 N

15 

10

15

10

Miscellaneous rocks

3*0 0.07 N 20 10 200 N 5 2,000 L 10 L

341 .02 N 20 L N N 20 5,000 10 L 10

342 .1 N 150 20 70 N 7 100 N L 15

the rich placer deposits on Napias and Beaver Creeks, tributaries of Panther Creek, which forms the northeast boundary of the study area.

The Blackbird district, which includes the Clear Creek-Upper Big Deer 

Creek study area, is the site of the most important cobalt deposit in the 

United States. Production from this district, mostly between 1951 and 

1968, included copper, cobalt, gold, silver, and nickel valued at more than 

$36 million. Mining claims in this district overlook Clear Creek, and mining operations are visible from the proposed wilderness. Claims in the Big 

Deer Creek drainage are within a mile of the study-area boundary. 

METHODS OF STUDY

Lode-mining-claim data pertaining to the Clear Creek-Upper Big Deer 

Creek study area were abstracted from Lemhi County records. Following 

a brief field reconnaissance to examine the few lode claim locations, the 

Bureau's work in the study area was directed to evaluation of gold placer 

deposits along the Salmon River and lower Panther Creek. Reconnais-
CLEAR CREEK-UPPER BIG DEER CREEK AREA, IDAHO C17

Creek-Upper Big Deer Creek study area Continued

Semiquanti tati ve spectrographi c analyses Continued 

(ppm)

. . Mo Sn Co Be Cr Ba Sr Ag As 

Sample (;) (1Q) (?) ()) (5) (|Q) (10Q) ( £) (]Q}

ROCK SAMPLES--Continued 

Unaltered rocks--Continued

319 N N

320 N N

321 N N

322 N N

32*4 N N

325 N L

326 N L

327 N N

328 N N

331 N N

335 N L

336 N 20

337 N 10

338 N N

339 N N

3<4<4 N N

N

10

10

N

N

7

7

N

N

5

L

N

N

N

N

7

1.0 15

1.0 50

L 50

L L

1.5 20

1.0 50

1.5 50

1.0 L

1.0 10

2.0 30

2.0 N

5.0 N

3.0 N

1.0 N

1.0 N

L 10

500

300

150

100

300

300

300

1 ,000

150

300

100

L

20

500

L

100

100

100

t

N

150

100

150

150

N

150

L

N

N

200

N

N

N N

N N

N N

N N

N N

N N

N N

N N

N N

N N

N N

N N

N N

N N

N N

N N

Quartz.

Schist.

Do.

Quartz.

Do.

Gneiss.

Do.

Do.

Do.

Do.

Crags pluton.

Alaskite float.

Do.

Gneiss.

Do.

Idaho batholith.

Altered rocks Continued

323 N N 

3*3 N N

7 1.0 30 

5 1.0 10

50 

500

100 

L

N N 

N N

Miscellaneous rocks Continued

3<40 N

3<4l N

3<42 N

N 15 1.0

N 500 N

N 7 N

L

10

30

150

L

200

N

N

1 ,000

N N

N 1 ,000

N N

Malachite.

Vein.

Tufa.

sance pan samples were taken, and test pits and trenches were dug into the 

larger deposits. Bulk samples from the pits and trenches were concentrated by using a vibrating mechanical sluice box and further concentrated by processing on a Wilfley table. Concentrates were amalgamated 

to determine gold content and some were examined petrographically.

The gold content of the placer gravels is expressed, in this report, in 

terms of dollars per cubic yard and(or) grams per cubic metre. In calculating the gold content in terms of dollars, a price of $100 per troy ounce was 

used.

LODE CLAIMS

The only known lode claims locations in the study area were a group 

called the White Rock, located in 1954 somewhere along Clear Creek. 

Vague descriptions indicate other claims are 1 mile south of Clear Creek, 

and overlooking Golden Trout Lake in the Bighorn Crags. These areas 

were examined, but no indication of prospecting or mining activities was 

seen.
CIS STUDIES RELATED TO WILDERNESS PRIMITIVE AREAS

PLACER DEPOSITS

The only mineral commodity of significance in the study area is gold. A 

variety of factors has caused the price of gold to be in a rising trend that 

began at $35 troy oz and has been higher than $200 troy oz since 1968. If a 

high price for gold is sustained, some of the gravel deposits along the 

Salmon River in the study area may be economically minable. Additional exploration would be required to determine the average grade and 

verify the economic feasibility of mining. Gold in gravel deposits along 

the river upstream from Middle Fork and on Panther Creek has resulted 

from erosion of gold-bearing rocks along the upper Salmon River and its 

tributaries (fig. 3). Downcutting of the Salmon and its tributaries has resulted in the perching of parts of ancient gold-bearing river bars in terraces or benches several hundred feet above the present river level. These 

bench gravels have contributed gold to lower benches through a reworking process.

The size and grade of the principal placer deposits are shown in table 2.

Fourteen major deposits (fig. 3) were sampled (12 by test pitting and 

trenching). A total of 12,246,000 yd3 (9,368,000 m3 ) of gravel is estimated to 

occur in these deposits. Two of these deposits extend outside the study 

area. In addition, 50,000-80,000 yd3 (38,000-61,000 m3 ) of auriferous 

gravel is estimated to occur in other small river bars and deposits.

Bench gravels, consisting of rounded and well-sorted igneous and 

metamorphic clasts as much as 2 feet (0.6 m) in diameter, contain most of 

the gold. Larger boulders possibly occur at depth in the thicker gravel. 

Bedrock schist and gneiss beneath the gravels have been scoured smooth, 

though not level, in the few places where they were observed. Interiors of 

the high benches were not examined or sampled. Freshly eroded exposures show that the composition of the high benches is about the same as 

that of the low benches.

Data for reconnaissance sample > shown in figure 3

Sample

No.

3...................

4...................

7.. .................

25

36 ...................

37

38..................

39...................

41..................

42.... ..............

Gold content

Cents per 

cubic yard1

........ 112

......... 15

15

......... < 2

......... 11

......... 12

......... 23

......... 29

5

......... 8

......... 47

......... 234

Grams per 

cubic metre

0.032

.454 

.061 

.061

.032 

<.008 

.045 

.049 

.093

.117 

.020 

.032 

.190 

.947

Remarks

Undisturbed gravel between 

old placer workings. 

Do. 

Do. 

Do.

Do. 

Beach gravel. 

Do. 

Do. 

Sand near bedrock.

Beach gravel. 

Do. 

Do. 

Do. 

Sandy clay on bedrock.

Calculated using a gold price of f 100.00 per troy ounce.
PLACER

1 Blue Mine

2 Golden Eage

3 Shell Creek

4 Colson Creek

5 Lake Creek

6 Ebeneezer

7 Poverty Flat

DEPOSITS

8 Homestake

9 Lower Owl Creek

10 Upper Owl Creek

11 Golden Queen

12 Garden Creek

13 Bear Gulch

14 Clear Creek

2 KILOMETRES

FIGURE 3. Placer deposits in the Clear Creek-Upper Big Deer 
C20 STUDIES RELATED TO WILDERNESS PRIMITIVE AREAS

TABLE 2. Principal gold placer deposits in the study area

Shell Creek....... ..............................................

Extent of 

deposit

(hectares)

5.0

.01

5 2

4.4

3.2

4.7

2.9

.... (4 )

.... 13.0

8.6

.... 10.3

.... 11.9

4.7

6.5

4 5

4.3

1.7

Overburden Gravel

(cubic (cubic metres) 

metres)

299,000 

0 

0 

0 

0

0 

138,000 

59,500 

(')

592,000 

0 

0 

283,000 

0

161,000 

48,600 

118,500 

0

298,000 

765 

285,000 

672,000 

288,000

52,000 

334,000 

222,000

(')

1,469,000 

275,000 

2,680,000 

820,000 

458,000

398,000 

455,000 

386,000 

265,000

Range of sample values 

of gold in gravel

grams per 

cubic metre

(') 

20.032-0.454 

.008 

< .008-1.057 

.008- .024

< .008- .202 

<.008 

.044 .563

2 .044- .093

(5 ) 

.061- .656 

<.008- .024

(') 

(')

<.008- .178 

.020- .575 

.062- .308 ( 6)

cents per 

cubic yard 

at $100 

per ounce

(') 

8-112 

<2 

< 2-261 

<2- 6

<2- 50 

<2 

11-139 

11- 23

(5 ) 

15-162 

<2- 6

0) (')

< 2- 44 

5-142 

15- 76

(6)

'Test pits and trenches did not penetrate through overburden.

2Reconnaissance samples.

'Includes only that part in the Clear Creek-Upper Big Deer Creek study area.

'Not estimated.

5Overburden has values as much as 0.019 grams per cubic metre; gravel was not 

sampled on the low bench. Values in top 6 feet of island were < 0.006 grams per cubic 

metre.

6Not sampled.

Alluvial fans that are nearly barren of gold cover most of the low 

benches and form a thin cover on the high benches. This alluvial material is poorly sorted, consisting of mostly silt and a few rounded cobbles and 

boulders as much as 10 feet (3 m) in diameter. The majority of the rock 

fragments are angular, with sharp edges which indicate that the fan 

material was derived from nearby canyon walls and tributary canyons.

PLACER MINING

Every placer deposit in the study area along the Salmon River contains 

some evidence of past mining activities, such as old workings, pieces of 

equipment and machinery, and claim corners. Although no records were 

found of gold production in the Clear Creek-Upper Big Deer Creek study 

area, evidence indicates that several thousand cubic yards of placer 

gravels have been processed. On the south side of the Salmon River, small 

mining operations have been conducted on Homestake, Ebeneezer, and 

Golden Eagle placers (fig. 3). The largest operations were on the north 

bank in the Cove Creek area, on the placer opposite Owl Creek, and in the 

Poverty Flat area. Easily accessible gravels between the large deposits were 

worked by small-scale methods to mine the high-grade gravel. The deposits at the mouth of Panther Creek and at Poverty Flat are covered by patented placer claims.

Development of the Salmon River placer deposits has been limited by
CLEAR CREEK-UPPER BIG DEER CREEK AREA, IDAHO C21

the large amount of overburden covering the river gravels. The overburden has resulted from rockfalls near steep Canyon walls and from the accumulation of large volumes of barren rock from tributary canyons. Placering on the south side of the river has been limited by lack of access across 

the river as well.

Mining activities were by small-scale methods, probably employing no 

more than four men. Gold recovery was by means of sluice boxes, rockers, 

and gold pans. There is some evidence that hydraulicking methods were 

used on a few deposits.

The relatively small size of the placer deposits and seasonal variations 

in the river level limit feasible mining methods to hydraulicking, dragline dredges, or open-pit operations. The most efficient method of processing the gravel above river level would probably be by hydraulicking. 

This method, however, would require costly safeguards against pollution of the river by muddy water or large volumes of washed gravel. Protection could be accomplished by construction of settling ponds and coffer dams around the deposit. However, a relatively small floating plant 

with dragline would be more feasible and muddy water could be confined 

to the pond.

The bedrock would have to be excavated a foot or more deep to recover 

any very high grade gold pockets in bedrock traps. There is no apparent 

problem with clay and no unusually large amounts of buried organic 

material.

SAMPLING

Prior to the beginning of trenching and pit digging into large deposits, 

a reconnaissance was made of the south bank of the Salmon River between Panther Creek and Middle Fork, and pan samples were taken. The 

locations of those samples taken between large deposits are shown in figure 3, and some of the analyses are shown in the accompanying table; 

other samples taken near the major gravel deposits are included in sections of this report describing the individual placers. Reconnaissance 

samples from along the Salmon River were usually taken from shallow 

holes dug 6-12 inches (15.3-30.6 cm) below the gravel surface, commonly 

near the high-water mark. Six of them were taken from bedrock. The 

reconnaissance samples were concentrated by panning; each sample consisted of one full 14- or 16-inch gold pan.

The larger placers were evaluated by means of 48 test pits and trenches. 

Pits were as much as 9 feet (2.8 m) deep and trenches down the faces of 

benches were as much as 48 feet (15m) long. No attempt was made to excavate below the water table. Of the 48 test holes, 7 were dug to the water table, 4 bottomed on boulders, and 7 reached bedrock. Many pits and 

trenches did not penetrate through alluvial fans or detritus to the underlying gravel. The thickness of the overburden where it was sampled is 

shown in the tables accompanying the illustrations, and an estimate of
C22 STUDIES RELATED TO WILDERNESS PRIMITIVE AREAS

the amount of overburden on each deposit is given in table 2.

At most test pits and trenches, 1 ft3 (0.028 m3 ) of sample was taken per 

foot (0.3 m) of pit depth. The swell factor averages about 30 percent. A 

total of 186 samples was taken at the 12 largest deposits. Samples were 

washed and concentrated by using a vibrating mechanical sluice box and 

were further concentrated by processing on a Wilfley table.

The gold values for concentrates containing only a few colors were estimated visually; all other concentrates were amalgamated and the gold 

was weighed. Final values per cubic yard were calculated using a gold 

price of $100 per troy ounce. The gold has an average fineness of 859 (859 

parts pure gold per thousand).

GOLD AND BLACK SANDS DISTRIBUTION

Gold was found in all but 13 of 186 samples taken at the 48 pits and 

trenches. Values were as much as $2.61/yd3 (1.06 g/m3 ) in these large sample volumes and as much as $2.33/yd3 (0.945 g/m3 ) in reconnaissance pan 

samples. All samples from undisturbed, well-rounded and well-sorted 

bench gravel contained gold.

Most of the samples from the overburden of alluvial-fan material contained some gold, which was probably derived from erosion of the high 

benches or from occasional flooding of the Salmon River. Gold values in 

the overburden were as much as $0.05/yd3 (0.020 g/m3 ) but nearly all overburden samples contained less than $0.02/yd3 (0.008 g/m3 ). The contact 

zone between alluvial fans and bench gravel is commonly marked by a 

sand layer in which there is a noticeable increase in the number of gold 

particles, compared with the values in poorly sorted detritus of the overburden.

In low-bench gravels, gold values increase with depth. The gold is not 

distributed evenly in the gravel, and the maximum values in benches are 

almost invariably on the underlying bedrock surface.

The gold values in the interiors of the high benches were not determined. Good values, however, were found near the contact of high and 

low benches.

In the gravel the black sand content varied from less than 1 lb/yd3 (0.06 

kg/m3 ) to 23 lb/yd3 (13.6 kg/m3 ); the average was 5 lb/yd3 (3.0 kg/m3 ) in 

the gravels along the Salmon River and 10 lb/yd3 (5.9 kg/m3 ) in the 

gravels along Panther Creek. Some layers, generally less than 1 foot (0.3 

m) thick, are composed almost entirely of black sands. Tests of these accumulations on river bars showed no appreciable gold values.

Concentrates of black sand from all samples contained an average of 25 

percent magnetic minerals, primarily magnetite; low-bench gravel contained 32 percent. Concentrates were scanned for fluorescence and radioactivity. Many had slightly anomalous radioactivity, which was probably from thorium in the mineral monazite or from uranium atoms in 

zircon crystal lattices. Measured radioactivity was as much as 10 percent
CLEAR CREEK-UPPER BIG DEER CREEK AREA, IDAHO C23

moiiazite-equivalent in concentrates from Poverty Flat. Only two concentrates contained as much as 20 percent by weight of zircon. The average zircon content is less than 0.2 lb/yd3 (120 g/m3 ) of gravel. Neither the 

radioactive minerals nor the zircon constitutes a potential resource.

DESCRIPTION OF PLACER DEPOSITS 

GARDEN CREEK PLACER

The Garden Creek placer, at the confluence of Garden Creek, Panther 

Creek, and the Salmon River (fig. 3, no. 12), is covered by the Bear patented placer claim (Mineral Survey 2471).

The patented claim consists of 26.9 acres (10.9 ha), but only about 12 

acres (4.9 ha) of the deposit are in the Clear Creek-Upper Big Deer Creek 

study area west of Panther Creek and south of the Salmon River (fig. 4).

EXPLANATION

Bedrock

Low-bench gravel

Test trench

Building

._44 

Reconnaissance sample

FIGURE 4. Garden Creek placer.
C24 STUDIES RELATED TO WILDERNESS PRIMITIVE AREAS

The bench gravel in the study area has been leveled and there is no 

indication of current activities.

A seismic spread near the center of the area of bench gravel indicates a 

depth to bedrock of about 35 feet (11 m); one-fourth of the distance is overburden of the Garden Creek alluvial fan (table 2). Trenches were dug at 

sites 1 and 2 to sample vertical sections of 33 feet (10m) and 18 feet (5.5 m) 

respectively, and samples representing depth intervals of 2-4 feet (0.6-1.2 

m) were analyzed. Trench 1 was entirely in the alluvial fan and trench 2 

was entirely in poorly sorted gravel. All trench samples contained values 

of less than $0.02/yd3 (0.008 g/m3 ). A reconnaissance pan sample contained less than $0.06/yd3 (0.024 g/m3 ).

GOLDEN QUEEN PLACER

The Golden Queen placer (fig. 1, No. 11) was operated in 1938-39 

(Lorain and Metzger, 1939, p. 79). Most of the gravel and the main placering area are on the north side of the river. Samples taken near bedrock on 

that side reportedly yielded gold values of $2.14-$2.85/yd3 (0.87-1.15 g/ 

m3 ). Past operations on the south bank are reported by local residents to 

have handled gravel worth up to $14.00/yd3 (5.8 g/m3 ). Floods andrevegetation have erased all traces of this former mining activity on the south 

bank. Samples 36-38 (fig. 3) taken during this current fieldwork gave 

values of $0.1 l-$0.23/yd3 (0.44-0.093 g/m3 ). Several thousand cubic yards 

of gravel remain (table 2).

UPPER OWL CREEK PLACER

The Upper Owl Creek placer (fig. 3, No. 10), opposite the mouth of 

Owl Creek (fig. 5), consists of 10.5 acres (4.25 ha) of bench gravel covered 

by alluvial fans. The deposit has a rolling surface 20-30 feet (6-9 m) above

Data for sample sites shown in figure 5

Depth interval

Site 

No.

1..........

2..........

3.... ......

4..........

5..........

43

19.

20

Feet

0 - 1.0

1.0- 4.0

4.0- 4.5

0 - 7.3

0 -12.1

12.1-14.1

14.1-16.1

16.1-18.1

18.1-21.1

0 -10.0

0 -17.0

17.0-19.0

19.0-21.5

21.5-24.5

24.5-27.5

Metres

0 -0.3

.3-1.2

1.2-1.4

0 -2.3

0 -3.7

3.7-4.3

4.3-5.0

5.0-5.3

5.3-6.2

0 -3.1

0 -5.1

5.1-5.8

5.8-6.3

6.3-7.5

7.5-8.2

Gold content

Cents per 

cubic yard1

6

20

52

<2

<2

<2

15

67

76

<2

< 2

37

37

60

21

8

3

6

Grams per 

cubic metre

0.024

.081

.211

<.008

<.008

<.008

.061

.271

.308

< .008

< .008

.150

.150

.243

.085

.032

.012

.024

Remarks

Sandy topsoil.

Silty sand.

Gravel.

Alluvium.

Do.

Gravel.

Do.

Do.

Do.

Alluvium.

Do.

Sand.

Sand and pea gravel.

Gravel.

Do.

Reconnaissance pan sample.

Do.

Do.

'Calculated using a gold price of $100.00 per troy ounce.
CLEAR CREEK-UPPER BIG DEER CREEK AREA, IDAHO C25

the river. This terrain is a result of alluvial fans having been deposited by 

outwash from steep tributary canyons. Evidence of mining activities 

includes several prospect pits at the upper end of the low bench and one 

old claim corner.

FEET

100 METRES

Bedrock

Old placer working

Building

, -20 

Reconnaissance sample

FIGURE 5. Upper Owl Creek placer.
C26 STUDIES RELATED TO WILDERNESS PRIMITIVE AREAS

A seismic spread on the low bench indicates that bedrock ranges from 30 

to 75 feet (9 to 23 m) below the surface. The volume of low-bench gravel is 

about 505,000 yd3 (390,000 m3 ) and is covered by about 155,000 yd3 (120,000 

m3 ) of overburden. Gold values of samples of the low-bench gravel averaged $0.38/yd3 (0.154 g/m3 ).

A total of 347,000 yd3 (268,000 m3 ) of gravel is estimated to be in a high 

bench whose top is about 100 feet (30 m) above the present river level. The 

high bench is estimated to have an average thickness of 50 feet (15 m) and 

was not sampled.

LOWER OWL CREEK PLACER

Lower Owl Creek placer (fig. 3, No. 9) includes about 29 acres (12 ha) of 

low-bench gravel as much as 25 feet (8 m) above river level, which is covered by a thick greater than 11 feet (3.5 m) layer of alluvial-fan detritus 

(fig. 6).

Seismic spreads in the low areas between the two principal fans indicate a depth to bedrock of 35-40 feet (10-12 m). About one-third the thickness is probably nearly barren overburden. The volume of the low-bench 

deposit is about 1,400,000 yd3 (1,100,000 m3 ) of which approximately 

1,000,000 yd3 (770,000 m3 ) is gravel (table 2). Test pits could not be 

excavated deep enough to sample the gravel beneath the alluvial-fan material. Only minor gold was recovered from the samples, including reconnaissance pan samples taken from shallow holes dug in the beach. The 

gravel, however, probably contains values similar to the Upper Owl 

Creek deposit. Gravel of apparently higher grade was mined directly 

across the river.

A remnant of gravel in a high bench is 100 feet (30 m) or more above the 

present river level. The high bench covers about 11.7 acres (4.7 ha) and is 

estimated to contain nearly 600,000 yd3 (460,000 m3 ) of gravel. Only one 

test pit was put down into the high-bench gravel. It did not extend 

through the alluvial-fan material into gravel. Samples contained values 

of less than $0.01/yd3 (0.004 g/m3 ).

Data for sample sites shown in figure 6 

Depth interval Gold content

Remarks

1.......

2. ......

3.......

4. .......

5........

21

22

23

24

.. 0 - 6.5

.. 0 - 8.9

.. 0 - 2.0

2.0- 5.0

5.0- 8.0

8.0-11.0

.. 0 - 5.0

.. 0 - 2.0

2.0-11.0

cub

0 -2.0

0 -2.7

0 - .6

.6-1.6

1.6-2.4

2.4-3.4

0 -1.5

0 - .6

.6-3.4

c yard1 cubic metre

2 <0.008

2 < .008

2 < .008

2 < .008

2 < .008

2 < .008

2 < .008

2 <..008

2 < .008

2 < .008

2 < .008

3 < .012

3 < 012

Alluvium.

Do.

Topsoil.

Alluvial-fan detritus.

Coarse black sand.

Fine silt.

Alluvium.

Do.

Do.

Reconnaissance pan sample.

Do.

Do.

Do.

'Calculated using a gold price of $100.00 per troy ounce.
CLEAR CREEK-UPPER BIG DEER CREEK AREA, IDAHO 

HOMESTAKE PLACER

C27

The Homestake placer (fig. 3, No. 8) is on the south bank of the Salmon 

River.

The volume of low-bench gravel, including the island at the northeast 

end, is estimated to be 1,900,000 yd3 (1,450,000 m3 ) (table 2). The low 

bench is covered by 774,000 yd3 (592,000 m3 ) of nearly barren alluvial fan 

and detritus. The tops of the fans are as much as 30 feet (9 m) above the 

river. Seismic tests indicate an average fan thickness of 15-20 feet (4.5-6 m) 

and depths to bedrock of 50 feet (15 m) or more over much of the deposit. 

About 360,000 yd3 (277,000 m3 ) of high-bench gravel occurs high on the 

valley wall.

A series of trenches (2-6, fig. 7) were dug and sampled in the face of an 

old placer-working at the contact of the high and low gravels (fig. 8). This 

was the site of the Homestake claim located and operated by G. W. Morris 

in the early 1940's. Mining probably consisted of hydraulicking of the

EXPLANATION

River bar 

Alluvial fan

X 3

Test pit

Old placer working

Low-bench detritus Building

High-bench gravel 

Bedrock

Reconnaissance sample

FIGURE 6. Lower Owl Creek placer.
C28 STUDIES RELATED TO WILDERNESS PRIMITIVE AREAS

bench gravel into a long sluice box. The pits represent a vertical section of 

about 30 feet (9 m). The high-bench gravel consists of a mixture of angular, subangular, and rounded gravels that form a relatively thin veneer 

over schist bedrock. Gravel in the gully below, in which the sluice box was 

placed, is well rounded. Gold values in the high-bench gravels averaged 

$0.44/yd3 (0.178 g/m3 ). The gold value of samples from the upper section 

of the low-bench gravel averaged $0.31/yd3 (0.126 g/m3 ).

EXPL AN AT ION

River bar 

Alluvial fan

Low- bench detritus

X7

Test pit

2to6 

y-<

Test trench

& 

Old placer working

High-bench gravel Building

Bedrock Reconnaissance sample

FIGURE 7. Homestake placer.
CLEAR CREEK-UPPER BIG DEER CREEK AREA, IDAHO

Data for sample sites shown in figure 7

C29

Depth interval

Site

No.

1.......

3

4.......

5

6.......

7.......

8.......

9.......

10.......

26.......

27.......

Feet

.... 0 1.25

1.25- 4.25 

4.25- 5.92

2.0- 6.5 

.... 0 2.0

2.0- 3.0 

3.0- 4.0

1.0- 4.0 

4.0- 5.5

1.0- 5.0 

5.0- 9.0

2.0- 6.0 

6.0- 8.0 

8.0-11.0

1.0- 5.0 

5.0- 7.0 

... 0 7.5

0 75

Metres ,

0 -1.1 

1.1-1.3 

1.3-1.8

.6-2.0

.6- .9 

.9-1.2 

0 - .5 

.5-1.2 

1.2-1.7

0 - .5 

.5-1.5 

1.5-2.8 

0 - .6 

.6-1.8 

1.8-2.4 

2.4-3.4

0 - .5 

.5-1.5 

1.5-2.1 

0 -2.2

0 -2.2 

0 -2.5

Gold content

^cya^d.

< 2 

<2 

<2 

15 

28

11 

14 

115

69 

44 

162

17 

63 

41 

6 

14 

46 

18

<2 

<2 

5 

<2

<2 

<2 

<2 

3

Grams per 

Cubic metre

< 0.008 

<.008 

<.008 

.061 

.113

.044 

.057 

.466 

.279 

.180 

656

.069 

.255 

.166 

.024 

.057 

.186 

.073

<.008 

<.008 

.020 

<.008

<.008 

<.008 

<.008 

'.012

Remarks

Island bar sand. 

Island bar gravel. 

Do. 

Topsoil. 

High-bench gravel.

Topsoil. 

High-bench gravel. 

High-bench gravel on bedrock. 

Topsoil. 

High-bench gravel. 

High-bench gravel on bedrock.

Topsoil. 

High-bench gravel. 

Do. 

Topsoil. 

Low-bench boulders and sand. 

Gravel. 

Do.

Topsoil. 

Detritus. 

Do. 

Alluvium.

Do. 

Do.

Reconnaissance pan sample (bedrock). 

Reconnaissance pan sample.

'Calculated using a gold price of $100.00 per troy ounce.

Four pits (7-10, fig. 7) were dug in the downstream part of the lower 

bench, but even though they were in the low area between fans, the bottom of the alluvial-fan material was not reached. Gold values were low.

A reconnaissance pan sample (not listed), taken at the small bench remnant about 100 feet (30 m) east of pit 8 (fig. 7) and about 200 feet (60 m) 

above the present river level, was found to contain several small flakes of 

gold.

POVERTY FLAT PLACER

Poverty Flat placer deposit (fig. 3 No. 7; fig. 9) is on both sides of the 

Salmon River. The north side is covered by the Daisy patented claim 

(Mineral Survey 2794).

On the south side of the river, the desposit consists of about 16 acres (6.5 

ha) of national forest land. Most of the low-bench placer on the south side 

is covered by poorly sorted alluvium derived from small tributary canyons. Only small remnants of high-bench gravels were found on the lower end. A seismic spread on the low bench between the two large alluvial 

fans indicated a depth to gravel of 4 feet (1.2m) and a total depth to bedrock of 30 feet (9 m). The fans, however, have an additional thickness of as 

much as 20 feet (6 m) above the bench. Total volume of the deposit is estimated to be about 730,000 yd3 (540,000 m3 ), including 520,000 yd3 

(385,000 m3 ) of gravel (table 2). The gold value of samples averages $0.187 

yd3 (0.073 g/m3 ).

The face of the upstream high-bench remnant, which is composed of 

loose, subangular gravel, was sampled by means of two offset trenches (2
C30 STUDIES RELATED TO WILDERNESS PRIMITIVE AREAS

and 4, fig. 9), and a pit (3, fig. 9). In the trench sections, gold values were as 

much as $0.30/yd3 (0.12 g/m3 ).

A reconnaissance pan sample (28, fig. 9) taken from the base of the 

downstream high bench, about 10 feet (3 m) above the river, contained a 

gold value of $1.80/yd3 (0.729 g/m3 ).

The bedrock slopes to near river level at test site 5 (fig. 9) where old placer workings had excavated into the base of the bench gravel. Gold values 

were as much as $0.44/yd3 (0.180 g/m3 ).

EBENEEZER PLACER

The area examined (fig. 4, No. 6) is upstream from Ebeneezer Creek (fig. 

10) and contains about 68,000 yd3 (52,000 m3 ) of gravel. The placer has an 

area of 4 acres (1.6 ha) and a maximum elevation of 10 feet (3 m) above 

river level; depth to bedrock averages about 14 feet (4.3 m), based on a seismic spread. A caved shaft and several pieces of equipment are evidence of 

old placer activity.

Gold values were $0.02-$0.1 I/yd3 (0.008-0.045 g/m3 ), except fora layer 

of pebbly sand which had a value of $.0.50/yd3 (0.203 g/m3 ).

FIGURE 8. Homestake placer workings in high-bench gravel.
CLEAR CREEK-UPPER BIG DEER CREEK AREA, IDAHO 

LAKE CREEK PLACER

C31

The Lake Creek placer is on private land (Homestead Entry Survey 426) 

belonging to Herman Nelson (fig. 3, No. 5). High-bench gravel underlies 

a terrace, which is about 100 feet (31 m) above the river, and covers about

100 METRES

FIGURE 9. Poverty Flat placer. 

Data for sample sites shown in figure 9

Depth interval

Site

No.

1. ........ .

2..........

3. .........

4. .........

5..........

28

Feet

0 -11.40

0 - 2.92

2.92- 5.50

5.50- 7.17

7.17- 9.84

9.84-10.84

10.84-14.84

0 - 2.80

2.8 - 5.50

0 - 2.00

2.0 - 4.25

4.25- 4.83

0 - 2.33

2.33- 6.25

6.25- 7.67

7.67- 8.67

Metres

0 -3.5

0 - .9

.9 -1.7

1.7 -2.15

2.15-2.95

2.95-3.3

3.3 -4.5

0 - .85

.85-1.7

0 - .62

.62-1.3

1.3 -1.45

0 - .75

.75-2.0

2.0 -2.3

2.3 -2.8

Gold

Cents per 

cubic yard1

<2

<2

<2

3

<2

< ?

< 2

14

12

<2

<2

<2

<2

< 2

20

44

180

Grams per 

cubic metre

< 0.008

< .008

<.008

.012

<.008

<.008

<.008

.057

.049

<.008

<.008

<.008

<.008

<.008

.081

.178

.729

Remarks

Alluvium.

Angular high-bench gravel.

Do.

Sand.

Angular high-bench gravel.

Do.

Do.

Alluvial-fan detritus.

Gravel.

Pebbly sand.

Sand.

Clayey sand.

Gravel.

Do.

Do.

Gravel on bedrock.

Reconnaissance pan sample

'Calculated using a gold price of $100.00 per troy ounce.
C32 STUDIES RELATED TO WILDERNESS PRIMITIVE AREAS

25 acres (10 ha) (fig. 11). The deposit is bisected by the canyon of Lake 

Creek. Some gravel was mined on the north side of the river, opposite the 

deposit. Sample localities were at each end of the deposit and were outEbeneezer 

Campground'

100 METRES

EXPLANATION

River bar

X7

Test pit

Alluvial fan

Low-bench gravel

High-bench gravel

Test trench

"9

Old placer working

 29

Reconnaissance sample

Bedrock

FIGURE 10. Ebeneezer placer. 

Data for sample sites shown in figure 10

Depth interval

Site 

No.

1.........

2.........

3.........

4. ........

29 .

Feet

0 -1.25

1.25-3.0

3.0 -5.0

5.0 -8.0

0 -2.5

2.5 -5.5

0 -2.5

2.0 -4.0

4.0 -6.0

6.0 -8.0

0 -4.2

4.2 -8.2

Metres

0 -0.4

.4 -9.2

9.2 -1.55

1.55-2.45

0 - .78

.78-1.65

0 - .65

.65-1.25

1.25-1.85

1.85-2.5

0 -1.25

1.25-2.5

Gold content

Cents per 

cubic yard1

<2

56

6

11

9

6

<2

<2

<2

5

<2

<2

5

Grams per 

cubic metre

< 0.008

.227

.024

.045

.036

.024

.008

.008

.008

.020

.008

.008

.020

Remarks

Sand.

Pebbly sand.

Rounded gravel.

Do.

Rounded high-bench gravel.

Do.

Rounded gravel.

Do.

Do,

Do.

Silty sand.

Clayey sand.

Reconnaissance pan sample.

'Calculated using a gold price of $100.00 per troy ounce.
CLEAR CREEK-UPPER BIG DEER CREEK AREA, IDAHO C33

side private property.

The volume of material of the whole deposit is estimated to be about 

3,500,000 yd3 (2,700,000 m3 ) (table 2). Insufficient data were obtained to 

estimate amounts of gold present in the Lake Creek high bench because

EXPLANATION

River bar

Alluvial fan 

tfigh-bench gravel

X'

Test pit

Test trench

Old placer working

Bedrock

Building

-31

Reconnaissance sample 

FIGURE 11. Lake Creek placer.
C34 STUDIES RELATED TO WILDERNESS PRIMITIVE AREAS

Data for sample sites shown in figure 11

Depth interval

Site

No.

1.. ........

3..........

30..........

31..........

32..........

33..........

Feet

0 - 4.0 

0 - 4.0 

2.0-10.0 

0 - 2.0 

2.0- 6.0 

6.0- 7.5 

7.5- 9.5

0 - 2.5 

2.5- 5.2 

5.2- 7.2 

7.2- 9.9

Metres

0 -1.25 

0 - .65 

.65-3.1 

0 - .65 

.65-1.85 

1.85-2.15 

2.15-2.9

0 - .78 

.78-1.55 

1.55-2.1 

2.1 -3.0

Gold content

Cents per 

cubic yard1

6 

<2 

<2 

<2 

<2 

<2 

<2

< 2 

< 2 

< 2 

< 2 

46 

49 

6 

5

Grams per 

cubic metre

0.025 

< .008 

< .008 

< .008 

< .008 

< .008 

< .008

<.008 

<.008 

<.008 

<.008 

.186 

.198 

.024 

.020

Remarks

Rounded high-bench gravel on bedrock. 

Rounded bench gravel. 

Do. 

Topsoil. 

Sand and boulder. 

Angular high-bench gravel. 

Black sand and pea gravel.

Angular high-bench gravel. 

Do. 

Sand. 

Angular high-bench gravel. 

Reconnaissance pan sample on bedrock. 

Reconnaissance pan sample. 

Do. 

Reconnaissance pan sample on bedrock.

'Calculated using a gold price of $100.00 per troy ounce.

depth to bedrock is probably in excess of 100 feet (31 m) and drilling or 

shaft sinking would be required for evaluation. Most samples were surficial and reflect the leaner gravels higher in the section. However, some 

reconnaissance samples showed values of $0.05-$0.46/yd3 (0.020-0.186

g/m3 ).

COLSON CREEK PLACER

The Colson Creek placer (fig. 3, No. 4) is a river bar extending about 0.3 

mile (0.5 km) along the south side of the Salmon River near Colson Creek. 

The bar covers 8 acres (3.2 ha), and seismic spread indicates that the depth 

to bedrock is a minimum of 30 feet (9 m) in the middle of the deposit. The 

volume, therefore, is in excess of 387,000 yd3 (296,000 m3 ) (table 2).

Three test holes were dug in the deposit: 8 feet (2.5 m) in the upstream 

end, 6.6 feet (2.0 m) deep to the water table near the center, and 8 feet (2.5 

m) in the downstream end. Because of accidental gold loss in processing, 

the actual values for these samples are unknown. Values of $0.06/yd3 

(0.024 g/m3 ) were recorded, but field estimates were several times higher.

Data for sample sites shown in fugure 12

Depth interval

Site

No.

1......... 

2.........

3......... 

8.........

9.........

11.........

34.........

35.........

Feet

0 - 4.0 

4.0- 5.0 

0 - 6.0 

6.0- 9.0 

0 -14.4

Metres

0 -1.25 

1.25-1.55 

0 -2.8 

2.8 -2.75 

0 -4.35

Gold content

Cents per 

cubic yard1

12 

21 

5 

8 

<2 

112

8 

86 

46 

142 

21 

6

Grams per 

Cubic metre

0.049 

.085 

.020 

.032 

<.008 

.454

.032 

.348 

.186 

.575 

.085 

.024

Remarks

Sand and pea gravel. 

Sand and pea gravel on large boulder. 

Sand. 

Gravel at water table. 

Alluvium. 

Reconnaissance pan sample.

Do. 

Do. 

Do. 

Do. 

Do. 

Do.

'Calculated using a gold price of f 100.00 per troy ounce.
CLEAR CREEK-UPPER BIG DEER CREEK AREA, IDAHO 

SHELL CREEK PLACER

C35

The Shell Creek placer (fig. 3, No. 3) is on private land (Homestead 

Entry Survey 624) owned by Fred Colson. The area of the gravel is about 

11 acres (4.5 ha), the thickness computed from seismic spread near the cen500 FEET

EXPLANATION

X2

Test pit

Test trench

Old placer working

Building

Bedrock

Reconnaissance sample 

FIGURE 12. Shell Creek placer.
C36 STUDIES RELATED TO WILDERNESS PRIMITIVE AREAS

ter of the deposit is about 37 feet (11 m). The volume of gravel is 590,000 

yd3 (455,000 m3 ) and the volume of overburden is 62,000 yd3 (48,000 m3 ).

Samples from test pits contained an average gold value of $0.1 I/yd3 

(0.045 g/m3 ). Values in reconnaissance pan samples, however, taken near 

old placer workings, were as much as $1.42/yd3 (0.575 g/m3 ) (fig. 12).

GOLDEN EAGLE PLACER

The Golden Eagle placer (fig. 3, No. 2) is on the south bank of the 

Salmon River 2 miles (3.2 m) upstream from the mouth of Middle Fork. It 

is a narrow deposit of high-bench gravel (fig. 13). The rounded gravel on 

the upstream end has a thickness of about 25 feet, and the overlying alluFEET

100 METRES

EXPLANATION

X 2

Test pit

Test trench

Bedrock

Old placer working

Building

Adit Inclined shaft

FIGURE 13. Golden Eagle placer.
CLEAR CREEK-UPPER BIG DEER CREEK AREA, IDAHO C37

vial-fan area at the center of the deposit has a maximum thickness of 

about 50 feet. The area of the high bench and fan is 7.2 acres (2.8 ha) and 

the volume of gravel is about 290,000 yd3 (220,000 m3 ) (table 2).

Placering has been done at the upper end of the deposit. Gold values of 

samples from the old workings ranged from $0.11-$1.39/yd3 (0.045-0.562 

g/m3 ), the highest value being on bedrock (fig. 13). The average gold 

value of placer gravel from the deposit, however, was $0.67/yd3 (0.271 

g/m3 ).

BLUE MINE

The placer at Blue Mine (fig. 3, No. 1) is on the south bank of the 

Salmon River, a short distance upstream from the mouth of Middle Fork. 

The claim was located in 1939 by Harry E. Jones. Mining operations were 

conducted along parts of a narrow stretch of beach about 100 feet (30 m) 

long and 10-20 feet (3-6 m) wide. Most of the beach is covered by coarse 

talus. The shallow depth to water probably prevented mining of all but 

the top few feet of gravel. Reconnaissance pan samples (3-5, fig. 3) from 

the top few inches of the beach material contained gold values ranging 

from $0.08 to $1.12/yd3 (0.032 to 0.454 g/m3 ) (table 3). About 1,000 yd3 (765 

m3 ) of auriferous gravel probably remain at the site (table 2).

BEAR GULCH FAN

The Bear Gulch alluvial fan (fig. 3, No. 13) covering 12.4 acres (5 ha) 

(table 2) is on the west side of Panther Creek 1 mile (1.6 km) from its confluence with the Salmon River. A test pit and trench were excavated in the 

alluvial-fan material to determine if gold was derived from the Bear 

Gulch drainage basin. Only traces of gold were detected. The pit and 

trench did not penetrate through the alluvial fan.

CLEAR CREEK DEPOSIT

The Clear Creek deposit (fig. 3, No. 14) contains high-bench gravel that 

is about 50 feet (15 m) thick with a volume of more than a million cubic

Data for sample sites shown in figure 13

Depth interval Gold content

Site

No. Feet Metres Cents per Grams per 

cubic yard1 cubic metre

1 ,

2......

3.......

.... 0 - 1.5

1.5-10.5 

10.5-11.5 

11.5-18.5 

18.5-20.5 

.... 0 - 4.2

4.2- 6.8

.... 0 - 1.3 

1.3- 5.3 

5.3- 7.3 

7.3- 9.6 

9.6-12.0 

12.0-17.0 

17.0-19.75

0 -0.5

.5-3.25 

3.25-5.0 

5.0 -5.6 

5.6 -6.25 0 -1.24

1.24-2.2

0 - .4 

.4 -1.66 

1.65-2.18 

2.18-2.6 

2.6 -8.54 

3.54-5.2 

5.2 -6.0

11

107 

24 

11 

139 

55

14

<2 

<2 

<2 

<2 

<2 

<2 

<2

0.045

.433 

.097 

.045 

.563 

.223

.057

.008 

.008 

.008 

.008 

.008 

.008 

.008

High-bench gravel. 

Do. 

Do. 

High-bench gravel on bedrock.

High-bench gravel on bedrock.

Topsoil. 

Talus and sand. 

Do. 

Silty sand. 

Sand. 

Alluvial-fan detritus. 

Sand.

'Calculated using a gold price of $100.00 per troy ounce.
C38 STUDIES RELATED TO WILDERNESS PRIMITIVE AREAS

yards. Additional high-bench gravel occurs south of Clear Creek but only 

that part of the bench north of the creek was sampled. The valley also contains several million cubic yards of low-bench gravel along the creeks.

EXPL A N AT I ON

t>

Low 

High

":: ;£ .":'

River bar

' A ' '. >'. 

'»' :: '4 ':*

Jluvial fan

-bench gravel

0 a °

0 f> (

-bench gravel h

Ws*

Bedrock

0

(

I

J

500 FEET 

I

I i

3 100 METRES

2X

Test pit

Test trench

Building

._ 45 

Reconnaissance sample

FIGURE 14. Clear Creek deposit.
CLEAR CREEK-UPPER BIG DEER CREEK AREA, IDAHO C39

The deposits in the study area are on privately owned land (Homestead 

Entry Survey 371).

In trench 1 (fig. 14), most of the gravel exposed has a gold content value 

of less than $0.01/yd3 (0.004 g/m3 ); the bottom 2.25 feet (0.8 m) has a value 

of $2.61/yd3 (1.06 g/m3 ). Reconnaissance sample 45, showing a value of 

$0.29/yd3 (0.117 g/m3 ), was taken near the middle of the section. Data are 

inconclusive regarding the gold content of the large low bench, as the pit 

(fig. 14, No. 2) did not penetrate through the sand into gravel.

Clear Creek No. 1 claim The Clear Creek No. 1 placer claim was reportedly located 1.5 miles (2.4 km) up Clear Creek in 1961. The location, 

however, was probably farther upstream, near the mouth of Rancherio 

Creek(sec. 12,T.22N.,R. 17 E.), where a piece of sluice box was found in 

the ruins of an old shed. The coca-mat liner in the bottom contained two 

very fine gold colors. Reconnaissance panning in the vicinity did not reveal a gold placer potential.

MISCELLANEOUS PLACERS AND RECONNAISSANCE SAMPLES

None of the miscellaneous placers that are found between the relatively 

large Salmon River deposits contain enough gravel to be developed by 

drag-line dredges or large-scale hydraulicking. Small operations utilizing portable placer machines or small-scale hydraulicking could possibly be successful where higher values are found and little "dead work" is 

required for development. Approximately 80,000 yd3 (60,000 m3 ) of these 

miscellaneous gravels are above the water table between Panther Creek 

and Middle Fork. Reconnaissance pan samples were taken and test pits 

and trenches were dug in the larger deposits (table 3).

CONCLUSIONS

On the basis of this study we conclude that there is little evidence of 

moderately large near-surface lode deposits of valuable metals in the study

Data for sample sites shown in figure 14

Depth interval Gold content

Sue

No. Pm Metres C ls ^ cubic \arcl 1

1 . ....... 0 - 3.75

3.75- 7.75

7.75-12.2

12.2 -15.9

15.9 -19.3

19.3 -23.5

23.5 -24.25

24.25-26.5

2Q.5 -31.75

31.75-36.5

36.5 -39.5

39.5 -45.75

45.75-48.0

2.......... 0 - 2.4

2.4 - 4.75

45......... .......

0 - 1.3

1.3- 2.3

2.3- 3.7

3.7- 4.9

4.9- 6.0

6.0- 7.1

7.1- 7.2

7.2- 8.2

8.2- 9.8

9.8-11.5

11.5-12.0

12.0-14.0

14.0-14.5

0 - .73

.73-1.45

< 2

< 9

< 2

5

< 2

<2

<2

2

2

< 2

2

2

261

< 2

< 2

29

< 0.008

< 008

< .008

.020

< .008

<.008

<.008

.008

.008

<.008

.008

.008

1.06

<.008

<.008

.117

Angular and rounded benc h gravel.

Subangular and rounded bench gravel.

Do.

Do.

Do.

Rounded benc h gravel.

Sand and gravel.

Well -sorted .sand and gravel.

Sand and gravel.

Do.

Do.

Coarse sand.

Bench gravel on bedrock.

Sandy gravel.

Sand and pea gravel at water table.

Rec onnaissanc e pan sample.

'Calculated using a gold price ol $100.00 per iro> ounc
C40 STUDIES RELATED TO WILDERNESS PRIMITIVE AREAS

area except tor a tin potential in the Upper Big Deer Creek drainage. 

While the surface lode potential of this area is low, there is somewhat 

greater potential for gold in bench placers along the Salmon River.

Most of the placer sampling consisted of near-surface samples, and data 

are lacking regarding the gold distribution in the interior of the benches 

and below the water table. There is some evidence that gold values may increase with depth as a bedrock surface is approached, and that significantly higher than average values should be found in selected channels in the bench gravels.

More than 12,000,000 yd3 (9,000,000 m3 ) of auriferous gravel is indicated 

in the bench deposits on the south side of the river. Some of these deposits 

are potential gold resources. A large unknown volume of gold-bearing 

gravel may be in the present river channel as a result of reworking of the 

bench deposits.

Average surf icial values of the bench gravels are estimated to range from 

$0.08 to $0.61/yd3 (0.032 to 0.247 g/m3 ). Insufficient sample data from 

near bedrock indicate the gold values of these portions range from $0.30 to 

$2.60/yd3 (0.122 to 1.05 g/m3 ). Most bench gravels are partly covered with 

as much as several tens of feet of virtually barren alluvial fan material. Additional exploration is necessary to delineate the average gold 

content and the economic feasibility of mining. Large deposits of bench 

gravels occur on the north side of the Salmon River, and potentially they 

could be developed with the gravel in the present stream channel and the 

bench gravel on the south side of the river in the study area.

REFERENCES CITED

Anderson, A. L., 1953, Gold-copper-lead deposits of the Yellowjacket district, Lemhi

County, Idaho: Idaho Bur. Mines and Geology Pamph. 94, 41 p. 

 1959, Geology and mineral resources of the North Fork quadrangle, Lemhi County,

Idaho: Idaho Bur. Mines and Geology Pamph. 118, 92 p. 

Canney, F. C., Hawkes, H. E., Richmond, G. M., and Vhay, J. S., 1953, A preliminary

report of geochemical investigations in the Blackbird district, Lemhi County, Idaho:

U.S. Geol. Survey open-file report no. 31. 

Cater, F. W., Pinckney, D. M., Hamilton, W. B., Parker, R. L., Weldin, R. D., Close,

T. J., and Zilka, N. T., 1973, Mineral resources of the Idaho Primitive Area and

vicinity, Idaho, with a section on the Thunder Mountain district, by B. F. Leonard,

and a section on Aeromagnetic interpretation, by W. E. Davis: U.S. Geol. Survey

Bull. 1304, 431 p. 

Giletti, B. J., 1966, Isotopic ages from southwestern Montana: Jour. Geophys. Research,

v. 71, no. 16, p. 4029-4036. 

Larsen, E. S., Jr., Gottfried, David, Jaffe, H. W., and Waring, C. L., 1958, Lead-alpha

ages of the Mesozoic batholiths of western North America: U.S. Geol. Survey Bull.

1070-B, p. 35-62. 

Larsen, E. S., Jr., and Schmidt, R. G., 1958, A reconnaissance of the Idaho batholith

and comparison with the southern California batholith: U.S. Geol. Survey Bull.

1070-A, p. 1-33. 

Lorain, S. H., and Metzger, O. H., 1939, Reconnaissance of placer-mining districts in

Lemhi County, Idaho: U.S. Bur. Mines Inf. Circ. 7082, 81 p.
CLEAR CREEK-UPPER BIG DEER CREEK AREA, IDAHO C41

Obradovich, J. D., and Peterman, Z. E., 1968, Geochronology of the Belt Series, Montana, 

in Geochronology of Precambrian stratified rocks, Internal. Conf., Edmonton, Alberta, 1967, Papers: Canadian Jour. Earth Sci., v. 5, no. 3, pt. 2, p. 737-747.

Romanowitz, C. M., Bennett, H. J., and Dare, W. L., 1970, Gold placer mining Placer 

evaluation and dredge selection: U.S. Bur. Mines Inf. Circ. 8462, 56 p.

Ross, C. P., 1934, Geology and ore deposits of the Casto quadrangle, Idaho: U.S. Geol. 

Survey Bull. 854, 135 p.

____1941, The metal and coal mining districts of Idaho, with notes on the nonmetallic 

mineral resources of the State: Idaho Bur. Mines and Geology Pamph. 57, Pt. 1, 

110 p.

Ruppel, E. T., 1975, Precambrian Y sedimentary rocks in east-central Idaho, Chap. 

A in Ruppel, E. T., Ross, R. J., Jr., and Schleicher, David, Precambrian and Lower 

Ordovician rocks in east-central Idaho: U.S. Geol. Survey Prof. Paper 889, 34 p.

Shockey, P. N., 1957, Reconnaissance geology of the Leesburg quadrangle, Lemhi 

County, Idaho: Idaho Bur. Mines and Geology Pamph. 113, 42 p.

Staley, W. W., 1946, Gold in Idaho: Idaho Bur. Mines and Geology Pamph. 68, 31 p.

U.S. Bureau of Mines Division of Nonferrous Metals, 1973, Gold: U.S. Bur. Mines Commodity Data Summaries, p. 60-61.

Vhay, J. S., 1948, Cobalt-copper deposits of the Blackbird district, Lemhi County, Idaho: 

U.S. Geol. Survey Strategic Minerals Inv., Prelim, rept. 3-219, 26 p.

Weis, P. L., Schmitt, L. J., Jr., and Tuchek, E. T., 1972, Mineral resources of the Salmon 

River Breaks Primitive area, Idaho, with a section on Aeromagnetic survey, by W. 

E. Davis: U.S. Geol. Survey Bull. 1353-C, 91 p.

West, J. M., 1973, Gold, in Minerals Yearbook 1971: U.S. Bur. Mines, v. 1, p. 539- 

560.

GOVERNMENT PRINTING OFFICE: 1975-677-340/1