Image Missing: Hearst Museum object titled Black-and-white negative, accession number 15-12184, described as Black and white negative. Site J 99 = 141, Mariposa County. Bedrock mortar at Site J 99, downstream ca 200' from petroglyphs. July 26, 1939. 2 3/8 square inches. 15-12184. Collector: Gordon W. Hewes. Donor: U.C. Central San Joaquin Valley Survey. Original number: 151.