Hunter, naturalist, and conservationist Charles Sheldon (1867-1928) collected, photographed, and observed wildlife. From 1903 to 1908 he devoted his time to the study of wildlife in the northwestern part of the North American continent, hunting grizzly bears in the upper Yukon and Denali. From 1912 to 1922, Sheldon shifted his focus to the Southwest, hunting and collecting desert bighorn sheep from Arizona to Sonora, Mexico. Sheldon was a key figure in both the development of the Mount McKinley National Park in Alaska and the establishment of the National Wildlife Refuge System. Hundreds of the biological specimens that Sheldon collected are now in the National Museum of Natural History at the Smithsonian Institution. For further biographical information, see The Wilderness of the Southwest.

This collection consists chiefly of two journals and photographic materials documenting Charles Sheldon's desert bighorn sheep collecting expeditions from 1912 to 1916. The second journal also documents his 1921-22 studies of the Seri Indians and Tiburon Island.