What counties was the California Gold Rush in?

The California Gold Rush primarily took place in several key counties, including Sacramento, Placer, Nevada, and El Dorado. These areas saw a massive influx of miners and settlers seeking gold after the discovery at Sutter's Mill in 1848. Other counties such as Amador, Tuolumne, and Mariposa also played significant roles in the gold mining activities. Overall, the Gold Rush dramatically transformed the region and contributed to California's rapid growth.