Inscription: Inscribed in the negative: "75"; printed on mount, upper edge: "WAR DEPARTMENT [+ insignia]// Explorations West of the 100th Meridian. Expedition of 1871. Lieut. Geo. M. Wheeler, Com'd'g."; lower edge: "T. H. O'Sullivan, Phot.// COLORADO RIVER SERIES// BLUFFS OPPOSITE BIG HORN CAMP, BLACN CAÑON, COLORADO RIVER// No. 75"..