Former gold-rush belt, Sierra Nevada foothills, central California, U.S. It was about 150 mi (240 km) long but only a few miles wide.
The gold rush was sparked by the 1848 discovery of placer gold on John Sutter 's property. The term mother lode evolved from the miners' concept of one main quartz vein with subsidiary offshoot veins. Exhaustion of the main gold streaks and a government-enforced price structure for gold caused mining operations to cease there in the 1930s. The area is dotted with scores of ghost camps and old mining towns.