all on mount, across top in letterpress: Explorations in Nevada and Arizona. War Department Corps of Engineers U.S. Army. [around insignia] Expedition of 1871.-Lieut. Geo. M. Wheeler, Com'd'g; across bottom: T.H. O'Sullivan, Phot. No. 11 / WALL IN THE GRAND CAÑON, COLORADA RIVER.
Mary and Dan Solomon; purchase and gift to NGA, 2006.