This collection is particularly strong in materials relating to Jamestown, which lay on Woods Creek and was an important early source of much gold (1849-1850). The town declined briefly (1852-1855) when surface gold played out, but revived again with the development of drift mine tunnels (1856-1885). Several items in the collection are probably evidence of sales during the period of decline. Over the years, Jamestown yielded an estimated $30 million, according to Gudde's California Gold Camps.

During the Gold Rush Tuolumne County was arguably the heartland of the Southern Mines. One of the original 27 counties (1850), Tuolumne has always had Sonora as her county seat. The major mining area occupied a huge basalt mesa, Table Mountain, that stretches some thirty miles along the Stanislaus River. Close to the northern end lies Columbia, best preserved and most thoroughly restored of the southern mining towns. Near it is SONORA and four miles south lies Jamestown. On the Tuolumne River are located Chinese Camp, Jacksonville and Big Oak Flat.

Collection is open for research.