Grass Valley – Nevada City Mining District
The gold-quartz mines of the Grass Valley – Nevada City District in Nevada County have been the most productive in the State of California. The mines in this district were known in California as the “Northern Mines”. Placer deposits in the Grass Valley – Nevada City District were first discovered during the gold rush of 1849 and subsequently gold was discovered in the quartz veins of Gold Hill in 1850.
The total gold production of Nevada County from 1849 through 1959 is estimated at 12.6M oz with 10.4M oz of lode gold and 2.2M oz of placer gold. The Grass Valley – Nevada City District was the third largest gold camp in the United States through to 1959 and virtually no production or exploration has occurred since that time.
The Empire, North Star, and Idaho-Maryland Mines have accounted for more than two-thirds of the Grass Valley production and had considerable influence on the economic life of the community. An estimated 5.8M oz gold was produced from the Empire-Star Mine and 2.4M oz gold from the Idaho-Maryland Mines. The two highly productive mines are only separated by approximately 2 miles. Empire Mine was in continuous operation from 1850 to 1956 except for the forced shutdown during WWII.