Written on back: "Camp Mather. 1948. Neg #20; San Francisco families, mother, ada and the kiddies lolling on the banks of Birch Lake, Camp Mather, after a cooling dip in its clear blue waters. Camp Mather, Tuolumne County, elevation 4500 feet. Camp Season - June 18 to Sept. 3. San Francisco Recreation Department, 304 Civic Auditorium."