The extraordinary body of work by photographer Carleton Watkins taken between 1858 and 1891 constitutes one of the longest and most productive careers in 19th-century American photography. Nearly 13,000 mammoth (18 x 22 inch) glass-plate negatives were produced, the majority of which exist in only one surviving print. Of these, fewer than 300 have ever been previously reproduced or exhibited. Drawing on painstaking research, the authors have assembled and catalogued all Watkins¿ known mammoth-plate photographs, including views of Yosemite, San Francisco, and the Pacific Coast. The work will contribute not only to a fuller understanding of this pioneering photographer but also portray the barely explored frontier in its final moments of pristine beauty.