6 views on "Survey of the Valley of the Colorado," mounts, most credited to Hillers. Views include Mamie's Fall, The Stone Man, The Camp Lullaby, Ward's Cascade, The Canon from above, and Island Monument. -- 16 views on "Survey of the Colorado River of the West" mounts, many credited to Hillers. Views include Cataract in a Cliff, The Shadow, Shin-Au-Av-Taw-Weap, Leaning Tower, The Abandoned Boat, The Chasm of the Colorado, and others. Some duplicates included. -- And one view on blank yellow mount, credited to Fennimore. View, titled Scene on the River, features a photographer (or photographer's assistant) with two boats, the one in the foreground carrying photography equipment including a covered camera on a tripod and what is likely a dark tent. Verso label identifies the view to Powell's Survey of the Rocky Mountain Region and provides series/image information. -- Together, 23 stereoviews, each 6 1/8 x 4 3/8 in., on cardstock mounts. Condition very good to fair, with toning, soiling, and wear to mount edges and corners present in all. Most with verso labels featuring image titles, some also featuring series information.