Kennedy and North Star Mine Model Exhibits, Jackson, Amador County
The Kennedy Mine headframe was one of the tallest in the world, until the 1928 surface fire burned all of the mine structures except the mine office and the stamp mill. The headframe was rebuilt and is 125 feet high. The mine was the deepest mine in North America with a shaft that went down into the earth 5,912 feet.
The second, and loudest model, in the exhibit is the stamp mill of the North Star Mine, which was between Sutter Creek and Amador City. A stamp mill is a large machine that crushes chunks of gold bearing ore.
Large chunks of ore were taken from the mine to the mill and were dumped onto a "grizzly" A "grizzly" was a metal grate with holes about 2 inches apart. The smallest pieces of ore would fall through the grate into the ore chute.
Pieces too big to fall through moved across the grate of the "grizzly" into the crusher. After being crushed to less than 2 inches, they would also fall into the ore chute and ended up at the stamp mill.
The stamp mill dropped a set of heavy steel stamps onto the ore pieces, pounding them until they were like fine sand. The fine pieces were taken for processing to extract the gold. A single stamp could crush 1.5 tons of ore. Stamp mills ran 24 hours a day, except for when repairs were made.
Here is a set of actual stamps utilized in the stamp mill.
The Kennedy Mine had a 100-stamp mill, one of the largest in the Mother Lode.