The placer deposits of Utah occur in two distinct types of environments. These are 1) placers found adjacent to, and derived from, gold, silver and base-metal deposits; and 2) placers found in major rivers and derived from unknown, distant sources.

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...

Common thought is the switchback slows the velocity of the rushing water and gold drops out from the cut bank to a fill gravel bar within or below the switchback. I am not going to disregard that model; however, I hope to improve upon it.