Keystone Mine, Amador City, Amador County

Located within the City limits of Amador City. One of the most profitable mines in the Mother Lode was the Keystone which producted $ 24,000,000. The Keystone mine was formed from several claims originally located in 1851. During the early oeriod of operations much high grade ore was produced so that dividends as high as $ 550 per share per month were declared.

By 1888 most of the high grade ore had been exhausted. Mining operation continied until the mine closed in 1919. From 1911 to 1919, the Keystone Mining Company operated the mine. and in 1920 the company gained control of the South Spring Hill mine adjining the Keystone property on the east side.

In 1933 the Keystone was reopened by Keystone Mines Syndicate. Production was underway by 1935 and continued until the fall of 1942 when the mine was closed down by governmental order L-208.

Ore was first cruched at the Keystone and then trucked to the Original Amador mine where it was milled and cyanuded. Just prior to the closing of the mine in 1942, about 100 men were employed at the mine and mill.