Inscription: Inscribed in the negative: "81"; 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// BLACK CAÑON, NEAR CAMP 8, LOOKING BELOW// No. 81".
Snyder, Joel. American Frontiers: The Photographs of Timothy H. O'Sullivan, 1867–1874. Millerton, N.Y.: Aperture, 1981. p. 20.
No. 81, Colorado River Series.