Custer County was so named for the gold mine that resides in the county. Custer County is named after the General Custer Mine that was discovered as early as 1876. The County is the third largest in the state of Idaho. Over 350,000 ounces of gold have came from the area.
Loon Creek District
One of the most popular and most well known districts in the county is the Loon Creek District. Scattered throughout the district are both lode and placer gold deposits. Try gold panning in and near Loon Creek. There is a gold mining ghost town known as Casto in the area just west of Challis, Idaho off of Highway 93. Near the townsite of Casto is a good place to find placer gold. The biggest and most productive mine the area was the Lost Packer Mine.
Yankee Fork District
Like many districts the Yankee Fork district was worked right up until World War II. Named after the Yankee Fork of the Salmon River, the Yankee Fork District was home to the Custer Mine, which produced over $8 million dollars of lode gold before 1900. The mill and mine closed in 1905 because apparently the deposit was only rich at a shallow depth. Total gold production for the Yankee Fork District, through 1959 was about 266,600 ounces. Gold was first discovered in Jordan Creek. Jordan Creek was a very rich creek in it’s day giving up an estimated 50,000 ounces of placer gold. Other mines in the area worth mention are the Bonanza Mine and Lucky Boy Mine (Two generic names for mines, used in the day.)
Exceptional gold has been found in the Stanley Basin, including along the Salmon River. Every creek or stream in the area produces some amount of gold, especially near the headwaters of Clayton. The Clayton area is surrounded by many gold mines including the so-named Clayton Mine and the area may be the best chance for a weekend prospector to find color. The Stanley Basin is found in Townships 10 and 11 North and Range 12 and 13 East. Other areas known for gold in the area are Stanley Creek, the area between Robinson Bar and Clayton.
The Nicholia district was mined in the early days. Many lead and silver mines produced a by product of gold.
In the Mackay Area the Copper mines produced a by product of gold in pyrite.
In Township 12 and 13 North and Range 18 East near Bayhorse the area copper and zinc mines produced a by product of gold.
Other Mines in Custer County were/are the Aztec Mine, Black Rock Mine, Buckskin Mine, Cal-Ida Mine, Champion Mine, Copper Basin Mine, Crater Mine, Darlington Shaft, Greenback Mine, Hermit Mine, Keystone Mine, Livingston Mine, Little Livingston Mine, Mountain King Mine, Mule Shoe Mine, Pacific Mine, Wildhorse Mines, Twin Apex Mine, Turtle Mine, Tango Mine, Sunbeam Mine, Star Hope Mine, Skylark Mine, Silverbell Mine, Silver Rute Mine, Seafoam Mine, Riverview Mine and many, many more.