There are a number of Tertiary river channels in the area, most of which trend south-southwest. They tend to be steep, narrow, and rich with coarse gold.

With successively lower temperatures as the water mixture cools, new sets of minerals are formed and many of those stable at a higher degree of heat became subject to alteration as the temperature progressively moved lower.

For approximately 30 years, the mines produced good ore, some so rich it was simply sent straight to bagging, bypassing milling and loaded directly on the rail cars.