Watkins, the consummate photographer of the American West, combined a virtuoso mastery of the difficult wet plate negative process with a rigorous sense of pictorial structure. For large-format landscape work such as Watkins produced along the Columbia River in Oregon, the physical demands were great. Since there was as yet no practical means of enlarging, Watkins's glass negatives had to be as large as he wished the prints to be, and his camera large enough to accommodate them. Furthermore, the glass negatives had to be coated, exposed, and developed while the collodion remained tacky, requiring the photographer to transport a traveling darkroom as he explored the rugged virgin terrain of the American West. The crystalline clarity of Watkins's remarkable "mammoth" prints is unmatched in the work of any of his contemporaries and is approached by few artists working today.