The Marie and James B. McMillan Photograph Collection (1900-1994) contains photographs of Marie and James B. McMillan and their families. The collection also includes photographs of their friends and professional associates, including journalist Hank Greenspun, Nevada civil rights pioneer J. David Hoggard, and entertainer Sammy Davis Jr. Marie McMillan is a former Las Vegas, Nevada flight instructor and one of the first women to work at the Nevada Test Site in Nye County, Nevada. James B. McMillan was the first African-American dentist to practice in Nevada, as well as a prominent Nevada civil rights leader.

The Howard Hughes Public Relations Photograph Collection depicts the activities of businessman Howard Hughes from 1930 to 1950. The photographs primarily depict aircraft flown by Hughes or designed by the Hughes Aircraft Company, including the XF-11 reconnaissance plane, the HK-1 Hercules (or "Spruce Goose"), and the Hughes H-1 Racer. The photographs also depict celebrations following Hughes's circumnavigation flight in New York City, New York and Chicago, Illinois in 1938. Lastly, the photographs include Hughes testifying in front of the Senate Special Committee to Investigate the National Defense Program in 1947.

The Helen J. Stewart Photographs depict the Stewart Family from approximately 1860 to 1950. The photographs primarily depict Helen J. Stewart and her children as well as the Stewart Ranch (also know as the Las Vegas Ranch) in Southern Nevada. The photographs include the early Las Vegas, Nevada town site, landscapes of Southern Nevada and the American Southwest, mines and mining camps, railroads and railroad workers, the Las Vegas Fort (also known as the Old Mormon Fort), hotels and early businesses in Las Vegas, Native Americans and Native American artifacts, and postcards.