Most of the commercial mineral deposits are on the south and southwest part of the range between Minersville and Milford, though small amounts of gold and silver have also been found in iron-rich outcrops in the basalt to the south of Milford.

Only the richest ores could be worked and shipped off for processing at a profit. As a result, early mining in the southern part of the Humboldt Range was short-lived. In the 1880s, placers were discovered in Spring Valley and American Valley on the east side of the range...

…it was immediately evident the previous owner had not been using a detector. During just a few months of working the dumps part-time, he recovered gold in quartz specimens valued in excess of $40,000.

Because tungsten minerals are heavy, exploration can be done using stream sediment samples. Prospectors looking for gold have found scheelite or wolframite in their placer concentrates, and in some cases this has led them to make important tungsten finds.