In January of 1848, James Marshall had a work crew camped on the American River at Coloma near Sacramento. The crew was building a saw mill for John Sutter. On the cold, clear morning of January 24, Marshall found a few tiny gold nuggets. Thus began one of the largest human migrations in history as a half-million people from around the world descended upon California in search of instant wealth.
The first printed notice of the discovery was in the March 15 issue of "The Californian" in San Francisco. Shortly after Marshall's discovery, General John Bidwell discovered gold in the Feather River and Major Pearson B. Reading found gold in the Trinity River. The California gold rush was soon in full sway.
In 1849, quartz mining began at the Mariposa mine in Mariposa County. Gold deposits were often found inside quartz veins. In 1850, California became a state. Also that year, gold-bearing quartz was found at Gold Hill in Grass Valley. This led to the development of the great underground mines in that district and a major industry the continued for more than 100 years.
In 1851, Gold was discovered in Greenhorn Creek, Kern County. This discovery led to the rush to the upper Kern River region. By 1852, California's annual gold production reached a then all-time high of $81 million.