The Mission of the Tuolumne County Historical Society shall be to discover, collect, preserve, and disseminate knowledge about the history of Tuolumne County and the State of California.
By 1960, the Tuolumne County jail, built in 1866, was obsolete and a new jail was constructed one block north. At the time, the Tuolumne County Museum and History Collection was located in the Veterans Memorial Hall on Washington Street in downtown Sonora. Carlo De Ferrari, County Clerk, was assigned the administrative responsibility of the museum after the retirement of Ruth Ann Newport. The Board of Directors, of the newly formed Tuolumne County Historical Society, discussed the need for expanding exhibit and storage space. At the request of the Society, the Tuolumne County Board of Supervisors designated the old jail as the Tuolumne County Museum and the Society became stewards of the Tuolumne County History Collection.
