James Savage's trading camp on the Merced River, 10 miles (16 km) west of Yosemite Valley,[11] was raided by Native Americans in December 1850, after which the raiders retreated into the mountains.[11] An appeal to the governor of California to put an end to this and other raids led to the formation of the Mariposa Battalion in 1851, and the start of the Mariposa War.[17]