The Hazel Baker Denton Photograph Collection (1910-1961) is comprised of photographic prints and one negative of the Denton family and friends, primarily taken in Nevada and Utah. Many photographs depict life in small Nevada towns, particularly Caliente. Photographs also depict Utah, Oregon, Washington D.C., and California, and unidentified desert and forest landscapes throughout the American West.

The Albert S. Henderson Photograph Collection (1860s-1959) primarily contains black-and-white photographic prints of Albert S. Henderson and his family. Also included in the collection are photographic prints of Henderson during his tenure as a Nevada legislator and district judge. Other materials include postcards, negatives, and a tintype.

The Peggie Kaltenborn Gambarana Photograph Collection consists of color photographic prints from approximately 1970 to 1979. The images are portraits of Robert J. Kaltenborn, Peggie Kaltenborn Gambarana, and Eddie Gambarana.

The Mike O'Callaghan Professional Papers (1943, 1968-2004) mainly consist of research files gathered by Mike O'Callaghan in his post-political capacity as executive editor of the Las Vegas Sun as well as owner and publisher of the Henderson Home News, Boulder City News, and Green Valley News. The papers also contain handwritten and typewritten drafts of O'Callaghan's "Where I Stand" article for the Las Vegas Sun, along with his reporter's notebooks, monthly planners, and photographic prints. The research files cover a wide variety of topics, including but not limited to environmental issues; nuclear waste; state and local politics; military and veterans affairs; foreign relations including Israel, Iraq, and Korea; and education. The collection also contains copies of speeches given by O'Callaghan as the 23rd Governor of Nevada between 1971 and 1979, some of which contain handwritten notations.