Group of two (2) albumen stereoviews from the Official War Department Corps of Engineers Survey Views of the American Southwest and Grand Canyon series. Views include: 

Both from the series Geographical and Geological Explorations and Surveys West of the 100th Meridian. Both mounted on yellow cardstock mounts with Expedition and Commander printed to recto. Versos bear illustrated series title, photographer credit, and view description. 

1. Timothy O'Sullivan (1840-1882), photographer. No. 43 [Pueblo San Juan, New Mexico].  Series: "Expedition of 1874 / 1st Lieut. Geo. M. Wheeler, Corps of Engineers Commanding." [Washington, D.C.: United States War Department, 1875]. 

Provenance: Official Library of Congress Division of Prints deaccession stamp to mount verso reads: "DUPLICATE / L.C. / 44931".

From the Wheeler Survey architectural and archaeological study showing survey members posed among the masonry walls and ruins of Pueblo San Juan along the north bank of the San Juan River in New Mexico. 

2. William Bell (1830-1910), photographer. No. 25 [The Grand Cañon of the Colorado, near the mouth of Kanab Creek]. Series: "Expedition of 1872 /  1st Lieut. Geo. M. Wheeler. Corps of Engineers, Commanding."

A spectacular landscape view showing the soaring sheer canyon walls with a solitary surveyor or photographer operating a field camera on a tripod in the foreground sand bar along the Colorado River. 

Led by Lieutenant George Montague Wheeler (1842-1905), the U.S. Army Corps of Engineers' Surveys West of the 100th Meridian produced some of the most enduring and visually striking photographic surveys in American history. Combining the technical mastery of Civil War veteran Timothy H. O’Sullivan and Philadelphia studio master William Bell, these official survey stereoviews were produced for government distribution and scientific study rather than mass-market commercial tourism.

The O'Sullivan view documents early Southwest archaeological exploration with notable Library of Congress provenance. The Bell view represents an iconic Western composition, capturing the immense scale of the Grand Canyon alongside the tools of early expeditionary photography.

[Wheeler Survey, 100th Meridian, Timothy H. O'Sullivan, William Bell, George M. Wheeler, Corps of Engineers, War Department, Grand Canyon, Colorado River, Kanab Creek, Pueblo San Juan, San Juan River, New Mexico, American Southwest, Western Exploration, Library of Congress Provenance] [Photography, Early Photography, Historic Photography, Stereoviews, Stereographs, Albumen Prints, Timothy O'Sullivan, William Bell, Western Photographers, Survey Photography]

Strong visual appeal throughout, featuring sharp focal clarity and balanced, warm tones. The yellow card mounts remain solid and flat with only minor edge bumping and gentle age toning.