Gold in Wyoming

Gold, the intrinsically valuable ‘royal metal’ derives its value from the combination of its rarity, and beauty along with its softness (H = 2.5 to 3), malleability, ductility, ease of alloying with other metals such as copper and silver, and its very high resistance to corrosion and tarnish. Various estimates place the average gold content of the Earth’s crust around 3.5 parts per billion (ppb) or roughly 0.0001 oz/ton. Although disseminated gold is widely distributed, concentrations greater than 1ppm or 1 g/tonne are near minimum for economic recovery in a modern low-grade large-tonnage gold mine. Higher grades are always desirable and are usually necessary to initiate mining prior to recovery of the lowest grade material.

Gold has a specific gravity of 19.3 – much heavier than the specific gravity of quartz (2.65), a common host rock for gold. Other host rocks may be heavier than quartz, but even the heaviest, such as banded iron formation, have specific gravities less than half that of gold. The great difference in weight between gold and its host rocks allows it to concentrate in placer deposits from which it can easily be recovered. Since earliest times, gold has been used for both objects of art and for coinage.

Gold and other metals have been mined from primary deposits in Precambrian rocks exposed in the cores of Wyoming’s mountain uplifts and in some Tertiary volcanic and intrusive rocks. Gold has also been mined from placer deposits concentrated by weathering and erosion of those primary occurrences.

Gold coins were in common use during the late 1800s and early 1900s.
Gold coins were in common use during the late 1800s and early 1900s.

History

Around 1842, travelers along the old emigrant trail (part of the Oregon Trail) first reported placer gold near the Sweetwater River in the area now known as the Lewiston district, located near the southern tip of the Wind River Range. Indian hostilities prevented serious prospecting until the 1860s. Wyoming’s first gold rush sprang from the 1867 discovery of bedrock-hosted gold west of the Lewiston district in what became the famous Carissa lode.

Carissa mine, 1989
Carissa mine, 1989

In 1869, the settlements of South Pass, Atlantic City, and Miners Delight boasted a combined population of more than 2,500. Gold production from the Carissa totaled between 50,000 and 180,000 ounces before 1911 (Hausel, 1989). Total production from Wyoming is unknown because no records were kept and few estimates were made before about 1900.

Mining districts were organized in several locations across Wyoming during the late 1860s and 1870s. The South Pass-Atlantic City district was first and foremost. Other districts discovered during that era of relatively high gold prices included Lewiston (about 12 miles southeast of the South Pass-Atlantic City district); Centennial Ridge, Douglas Creek, Gold Hill, Keystone, and New Rambler (all in the Medicine Bow Mountains); Seminoe Mountains; Copper Mountain in the Owl Creek Mountains; and Mineral Hill in the Black Hills. Recent gold exploration activity in Wyoming has emphasized both historic mining districts as well as more recent discoveries.

Gold districts and mineralized areas of Wyoming.
Gold districts and mineralized areas of Wyoming.

The dramatic rise of gold prices to more than $900/ounce beginning in 2005 led to renewed interest in Wyoming gold.

Current Gold prices provided by Infomine.

Individual prospectors, recreationists, and a few major companies have recently explored historic gold districts and potential new deposits.

Information on most of Wyoming’s gold and precious metals deposits can be found in the following recommended publications by the Wyoming State Geological Survey (WSGS):

WSGS Bulletin 68, The geology of Wyoming’s precious metal lode and placer deposits, by W. Dan Hausel, 1989, 248 p.

WSGS Bulletin 70, Copper, lead, zinc, molybdenum, and other associated metal deposits of Wyoming, by W. Dan Hausel, 1997, 229 p.

WSGS Bulletins 68 and 70.
WSGS Bulletins 68 and 70.

The rapid climb of gold prices to new heights during the last several years continues to drive commercial gold exploration across Wyoming. Amateur prospecting for gold in Wyoming also enjoys renewed popularity. WSGS Information Pamphlet 9, Searching for gold in Wyoming by W. Dan Hausel (2002), gives detailed information for prospectors interested in exploring Wyoming for gold.

Click on the following links for more information on gold in Wyoming.