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Prospecting for Gold in the United States of America:
by Harold Kirkemo
Anyone who pans for gold hopes to be rewarded by the glitter
of colors in the fine material collected in the bottom of the
pan. Although the exercise and outdoor activity experienced in
prospecting are rewarding, there are few thrills comparable to
finding gold. Even an assay report showing an appreciable content
of gold in a sample obtained from a lode deposit is exciting. The
would-be prospector hoping for financial gain, however, should
carefully consider all the pertinent facts before deciding on a
prospecting venture.
Only a few prospectors among the many thousands who searched
the western part of the United States ever found a valuable
deposit. Most of the gold mining districts in the West were
located by pioneers, many of whom were experienced gold miners
from the southern Appalachian region, but even in colonial times
only a small proportion of the gold seekers were successful. Over
the past several centuries the country has been thoroughly
searched by prospectors. During the depression of the 1930's,
prospectors searched the better known gold-producing areas
throughout the Nation, especially in the West, and the
little-known areas as well. The results of their activities have
never been fully documented, but incomplete records indicate that
an extremely small percentage of the total number of active
prospectors supported themselves by gold mining. Of the few
significant discoveries reported, nearly all were made by
prospectors of long experience who were familiar with the regions
in which they were working.
The lack of outstanding success in spite of the great
increase in prospecting during the depression in the 1930's
confirms the opinion of those most familiar with the occurrence
of gold and the development of gold mining districts that the
best chances of success lie in systematic studies of known
productive areas rather than in efforts to discover gold in
hitherto unproductive areas. The development of new, highly
sensitive, and relatively inexpensive methods of detecting gold,
however, has greatly increased the possibility of discovering
gold deposits which are too low grade to have been recognized
earlier by the prospector using only a gold pan. These may be
large enough to be exploited by modern mining and metallurgical
techniques. The Carlin mine near Carlin, Nev., is producing gold
from a large low-grade deposit that was opened in 1965 after
intensive scientific and technical work had been completed.
Similar investigations have led to the more recent discovery of a
Carlin-type gold deposit in Jerritt Canyon, Nev.
Many believe that it is possible to make wages or better by
panning gold in the streams of the West, particularly in regions
where placer mining formerly flourished. However, most placer
deposits have been thoroughly reworked at least twice--first by
Chinese laborers, who arrived soon after the initial boom periods
and recovered gold from the lower grade deposits and tailings
left by the first miners, and later by itinerant miners during
the 1930's. Geologists and engineers who systematically
investigate remote parts of the country find small placer
diggings and old prospect pits whose number and wide distribution
imply few, if any, recognizable surface indications of
metal-bearing deposits were overlooked by the earlier miners and
prospectors.
One who contemplates prospecting for gold should realize
that a successful venture does not necessarily mean large profits
even if the discovery is developed into a producing mine.
Although the price of gold has increased significantly since 1967
when the fixed price of $35 an ounce was terminated, the
increases in the cost of virtually every supply and service item
needed in prospecting and mining ventures have kept profit
margins at moderate levels, particularly for the small mine
operator. In general, wide fluctuations in the price of gold are
not uncommon, whereas inflationary pressures are more persistent.
The producer of gold, therefore, faces uncertain economic
problems and should be aware of their effects on his
operation.
Today's prospector must determine where prospecting is
permitted and be aware of the regulations under which he is
allowed to search for gold and other metals. Permission to enter
upon privately owned land must be obtained from the land owner.
Determination of land ownership and location and contact with the
owner can be a time-consuming chore but one which has to be done
before prospecting can begin.
Determination of the location and extent of public lands
open to mineral entry for prospecting and mining purposes also is
a time consuming but necessary requirement. National parks, for
example, are closed to prospecting. Certain lands under the
jurisdiction of the Forest Service and the Bureau of Land
Management may be entered for prospecting, but sets of rules and
regulations govern entry. The following statement from a pamphlet
issued in 1978 by the U.S. Department of the Interior and
entitled "Staking a mining claim on Federal Lands" responds to
the question "Where May I Prospect?"
There are still areas where you may prospect,
and if a discovery of a valuable, locatable mineral is made, you
may stake a claim. These areas are mainly in Alaska, Arizona,
Arkansas, California, Colorado, Florida, Idaho, Louisiana,
Mississippi, Montana, Nebraska, Nevada, New Mexico, North
Dakota, Oregon, South Dakota, Utah, Washington, and Wyoming.
Such areas are mainly unreserved, unappropriated Federal
public lands administered by the Bureau of Land Management
(BLM) of the U.S. Department of the Interior and in national
forests administered by the Forest Service of the U.S.
Department of Agriculture. Public land records in the proper BLM
State Office will show you which lands are closed to mineral
entry under the mining laws. These offices keep up-to-date land
status plats that are available to the public for inspection. BLM
is publishing a series of surface and mineral ownership maps that
depict the general ownership pattern of public lands. These maps
may be purchased at most BLM Offices. For a specific tract of
land, it is advisable to check the official land records at the
proper BLM State Office.
Successful gold mining under present conditions is a large-scale
operation, utilizing costly and sophisticated machinery capable
of handling many tons of low-grade ore each day. The grizzled
prospector with a burro is no longer a significant participant in
the search for mineral deposits, and the small producer accounts
for only a minor share of the total production of metals
including gold.
Some degree of success in finding gold still remains for
those choosing favorable areas after a careful study of mining
records and the geology of the mining districts. Serious
prospecting should not be attempted by anyone without sufficient
capital to support a long and possibly discouraging campaign of
preliminary work. The prospective gold seeker must have ample
funds to travel to and from the region he selects to prospect and
to support the venture. He must be prepared to undergo physical
hardships, possess a car capable of traveling the roughest and
steepest roads, and not be discouraged by repeated
disappointments. Even if a discovery of value is not found, the
venture will have been interesting and challenging.
Locations of important gold-producing districts of the
United States are shown in some of the reports of the Geological
Survey listed at the back of this pamphlet. Geological agencies
of the principal gold-producing States where additional
information may be obtained also are listed. Information may be
obtained, too, from U.S. Bureau of Mines State Liaison offices
located in the capital cities of most States.
Placer Deposits
A placer deposit is a concentration of a natural material
that has accumulated in unconsolidated sediments of a stream bed,
beach, or residual deposit. Gold derived by weathering or other
process from lode deposits is likely to accumulate in placer
deposits because of its weight and resistance to corrosion. In
addition, its characteristically sun-yellow color makes it easily
and quickly recognizable even in very small quantities. The gold
pan or miner's pan is a shallow sheet-iron vessel with sloping
sides and flat bottom used to wash gold-bearing gravel or other
material containing heavy minerals. The process of washing
material in a pan, referred to as "panning," is the simplest and
most commonly used and least expensive method for a prospector to
separate gold from the silt, sand, and gravel of the stream
deposits. It is a tedious, back-breaking job and only with
practice does one become proficient in the operation.
Many placer districts in California have been mined on a
large scale as recently as the mid-1950's. Streams draining the
rich Mother Lode region--the Feather, Mokelumne, American,
Cosumnes, Calaveras, and Yuba Rivers--and the Trinity River in
northern California have concentrated considerable quantities of
gold in gravels. In addition, placers associated with gravels
that are stream remnants from an older erosion cycle occur in the
same general area.
Much of the gold produced in Alaska was mined from placers.
These deposits are widespread, occurring along many of the major
rivers and their tributaries. Some ocean beach sands also have
been productive. The principal placer-mining region has been the
Yukon River basin which crosses central Alaska. Dredging
operations in the Fairbanks district have been the most
productive in the State. Beach deposits in the Nome district in
the south-central part of the Seward Peninsula rank second among
productive placer deposits of Alaska. Other highly productive
placers have been found in the drainage basin of the Copper River
and of the Kuskokwim River.
In Montana, the principal placer-mining districts are in the
southwestern part of the State. The most productive placer
deposit in the State was at Alder Gulch near Virginia City in
Madison County. Other important placer localities are on the
Missouri River in the Helena mining district. The famous Last
Chance Gulch is the site of the city of Helena. There are many
districts farther south on the headwaters and tributaries of the
Missouri River, especially in Madison County which ranks third in
total gold production in the State. Gold has been produced at
many places on the headwaters of the Clark Fork of the Columbia
River, particularly in the vicinity of Butte. Placer production
from the Butte district, however, has been over-shadowed by the
total output of byproduct gold recovered from the mining of lode
deposits of copper, lead, and zinc.
Idaho was once a leading placer-mining State. One of the
chief dredging areas is in the Boise Basin, a few miles northeast
of Boise, in the west-central part of the State. Other placer
deposits are located along the Salmon River and on the Clearwater
River and its tributaries, particularly at Elk City, Pierce, and
Orofino. Extremely fine-grained (or "flour") gold occurs in sand
deposits along the Snake River in southern Idaho.
Placers in Colorado have been mined in the Fairplay district in
Park County, and in the Breckenridge district in Summit County.
In both areas large dredges were used during the peak activity in
the 1930's.
The most important mining regions of Oregon are in the
northeastern part of the State where both lode and placer gold
have been found. Placer gold occurs in many streams that drain
the Blue and Wallowa Mountains. One of the most productive placer
districts in this area is in the vicinity of Sumpter, on the
upper Powder River. The Burnt River and its tributaries have
yielded gold. Farther to the west, placer mining (particularly
dredging) has been carried on for many years in the John Day
River valley.
In southwestern Oregon, tributaries of the Rogue River and
neighboring streams in the Klamath Mountains have been sources of
placer gold. Among the main producing districts in this region
are the Greenback district in Josephine County and the Applegate
district in Jackson County.
Minor amounts of placer gold have been produced in South
Dakota (the Black Hills region, particularly in the Deadwood
area, and on French Creek, near Custer) and in Washington (on the
Columbia and Snake Rivers and their tributaries).
In addition to these localities, placer gold occurs along
many of the intermittent and ephemeral streams of arid regions in
Nevada, Arizona, New Mexico, and southern California. In many of
these places a large reserve of low-grade placer gold may exist,
but the lack of a permanent water supply for conventional placer
mining operations requires the use of expensive dry or semidry
concentrating methods to recover the gold.
In the eastern States, limited amounts of gold have been
washed from some streams draining the eastern slope of the
southern Appalachian region in Maryland, Virginia, North
Carolina, South Carolina, Georgia, and Alabama. Many saprolite
(disintegrated somewhat decomposed rock that lies in its original
place) deposits in this general region also have been mined by
placer methods. Small quantities of gold have been mined by
placer methods in some New England States. Additional placer
deposits may be discovered in the East, but prospecting will
require substantial expenditures of time and money. The deposits
probably will be low grade, difficult to recognize, and costly to
explore and sample. Moreover, most of the land in the East is
privately owned, and prospecting can be done only with the prior
permission and agreement of the land owner.
Lode Gold
Lode gold occurs within the solid rock in which it was
deposited. Areas likely to contain valuable lode deposits of gold
have been explored so thoroughly that the inexperienced
prospector without ample capital has little chance of discovering
a new lode worth developing. Most future discoveries of workable
lode gold ore probably will result from continued investigations
in areas known to be productive in the past. The districts in
which such new discoveries of gold may be possible are too
numerous to be listed in detail in this pamphlet. Some of the
famous districts are: in California, the Alleghany, Sierra City,
Grass Valley, and Nevada City districts, and the Mother Lode
belt; in Colorado, the Cripple Creek, Telluride, Silverton, and
Ouray districts; in Nevada, the Goldfield, Tonopah, and Comstock
districts; in South Dakota, the Lead district in the Black Hills;
and in Alaska, the Juneau and Fairbanks districts. Deposits in
these districts generally are gold-quartz lodes.
Prospecting for lode deposits of gold is not the relatively
simple task it once was because most outcrops or exposures of
mineralized rock have been examined and sampled. Today's
prospector must examine not only these exposures, but also broken
rock on mine dumps and exposures of mineralized rock in
accessible mine workings. Gold, if present, may not be visible in
the rock, and detection will depend on the results of laboratory
analyses. Usually, samples of 3 to 5 pounds of representative
mineralized rock will be sent to a commercial analytical
laboratory or assay office for assay. Obviously, knowledge about
the geological nature of gold deposits and particularly of the
rocks and deposits in the area of interest will aid the
prospector.
There are many publications of interest to those seeking
more information about gold. The following list is
representative. Anyone contemplating a prospecting venture or
mining operation should consult some or all of these and other
publications as well to become better informed on this
fascinating and challenging subject. Many papers, maps, and
articles on gold and related heavy metals were published on the
results of investigations conducted in the mid- to late-1960's by
the U.S. Geological Survey and the U.S. Bureau of Mines. Titles
and instructions for ordering many of these appear in the
publication catalogs of each agency. Some may be out of print but
may be consulted in libraries of the two agencies, and in many
city, college, and university libraries.
Selected References on Gold
- Cobb, E. H., 1984, Lode gold and silver occurrences in
Alaska:
U.S. Geological Survey Mineral Resource Map, MR-84, scale
1:2,500,000.
- _____, 1984, Placer gold occurrences in Alaska: U.S.
Geological
Survey Mineral Resource Map, MR-83, scale 1:2,500,000.
- Jones, Robert S., and Fleischer, Michael, 1969, Gold in
minerals
and the composition of native gold: U.S. Geological Survey
Circular 612. 17 p.
- Koschmann, A. H., and Bergendahl, M. H., 1962, Gold in the
United
States, exclusive of Alaska and Hawaii: U.S. Geological Survey
Mineral Resource Map, MR-24, scale 1:3,168.000.
- _____, 1968, Principal gold-producing districts of the United
States: U.S. Geological Survey Professional Paper 610, 283 p.
- Ransom, Jay Ellis, 1975, The gold hunter's fieldbook: New
York,
Harper & Row, 367 p.
- Simons, Frank S., and Prinz, William C., 1973, Gold in United
States Mineral Resources: U.S. Geological Survey Professional
Paper 820, p. 263-275.
- Theobald, Paul K., Jr., 1957, The gold pan as a quantitative
geologic tool: U.S. Geological Survey Bulletin 1071-A. 54 p.
- U.S. Bureau of Land Management, 1977, Patenting a mining
claim on
Federal lands: U.S. Government Printing Office, 21 p.
- _____, 1978, Staking a mining claim on Federal lands: U.S.
Government Printing Office, 18 p.
- U.S. Bureau of Mines, 1967, Production potential of known
gold
deposits in the United States: U.S. Bureau of Mines Information
Circular 8331, 24 p.
- U.S. Forest Service, 1971, Mining and mining claims in
National
Forest Wildernesses: U.S. Government Printing Office, U.S.
Department of Agriculture. 19 p.
- _____, 1975, Mining in National Forests: Current Information
Report No. 14, U.S. Department of Agriculture, 20 p.
- U.S. Geological Survey, 1978, Suggestions for prospecting:
pamphlet, 24 p.
- ____, 1979, Gold: pamphlet, 24 p.
- Ward, F. N., Nakagawa, H. M., Harms, T. F., and VanSickle, G.
H.,
1969, Atomic-absorption methods of analysis useful in geochemical
exploration: U.S. Geological Survey Bulletin 1289, 45 p.
- Wells, John H., 1969, Placer examination-principles and
practice: U.S. Bureau of Land Management Technical Bulletin 4,
209 p.
- West, J. M., 1971, How to mine and prospect for gold: U.S.
Bureau
of Mines, Information Circular 8517. 43 p.
- ____, 1980, Gold in Mineral facts and problems: U.S. Bureau
of
Mines Bulletin 671, p. 367-381.
- Wise, Edmund M., 1964, Gold, recovery, properties, and
applications: New York, D. Van Nostrand, 367 p.
* U.S. GOVERNMENT PRINTING OFFICE: 1991-287-748
This publication is one of a series of general interest
publications prepared by the U.S. Geological Survey to
provide information about the earth sciences, natural resources,
and the environment. To obtain a catalog
of additional titles in the series "General Interest Publications
of the U.S. Geological Survey," write:
U.S. Geological Survey
Information Services
P.O. Box 25286
Denver, CO 80225
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