TIMOTHY O'SULLIVAN (1840-1882) & WM. H. JACKSON (1843-1942) North Fork Cañon, Sierra Blanca Creek, Arizona * The Loop Above Georgetown Union Pacific Rv. A pair of albumen prints, the images measuring 7 7/8x10 3/4 and 9 1/2x12 1/2 inches (20.1x27.3 and 24.1x31.8 cm.) the first on the two-toned Wheeler Survey mount 16x20 inches (40.6x50.8 cm.), with O'Sullivan's credit, title, plate no. 4, the U.S. Army Corps of Engineers Geological Survey credit and date, and the imprint of the War Department, Corps of Engineers, on mount recto; the second flush mounted, with Jackson's credit, inventory number, and caption, on recto, and notations, in pencil, a hand stamp, and a partial label on mount verso. 1873, circa 1875
