Hardrock gold deposits are more varied in mineralogy and geology than placer deposits, and prospecting methods can be very different for different types of deposits. As with placer gold, the sophistication of methods used to prospect for hardrock gold vary with the financial resources of the prospector.
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.
How to Mine and Prospect for Placer Gold [J. M. West, Depart U. S. Department of the Interior] on . *FREE* shipping on qualifying offers. Increased leisure time and increased interest in the out-of-doors is leading more and more families to experiment with placer mining of gold
If the overburden only contains $2 of gold per yard, and your mining cost is $5 per yard, then you are losing $3 for every yard put through the wash plant. On the other hand, if you can strip low-grade overburden for $1 per yard, then you have saved $2 per yard which can be directed toward mining the pay gravels. Often, new miners leave a lot of gold values in the bedrock.