The Stamp Mill was a method of Gold extraction and one very common in the Kern River Valley.  Depending on the size of the operation, could range from 1 to 80 stamps.

Our huge 3 Stamp Mill rescued by the Forest Service, was given to the Museum in 2005.  It is an excellent depiction of how Gold Ore was crushed.

This Mill would be used in a small operation, probably located near a river and powered by a water wheel of some kind. 

Ore was introduced into the hopper and the stamp was lifted by a cam action, allowing it to drop with some force crushing the ore to almost a powder, freeing the gold. 

Gold was extracted from the crushed ore by allowing the water to carry it across a metal plate coated with mercury. 

The mercury would pull the gold from the slurry, then it was heated until at a low temperature; it would boil away leaving the gold amalgam.  The mercury would be recaptured, cooled and becoming a liquid, it was used again. 

The process was highly toxic and many miners died with accumulated mercury blood poisoning after constantly inhaling the fumes.