Materials depict Las Vegas, Nevada from 1904 to 1973 as it related to the Union Pacific Railroad. The photographs primarily depict early Las Vegas buildings, including Fremont Street, the Arizona Club, the Mormon Fort, and the Hotel Nevada. The photographs also depict Union Pacific officials meeting with Las Vegas officials, including the Las Vegas Chamber of Commerce. Finally, the photographs depict the Union Pacific depots in Las Vegas.

Materials depict the construction of Boulder City, Nevada and the Hoover (Boulder) Dam from 1930 to 1935. The photographs primarily depict construction of the master planned community of Boulder City, which was built to house workers during the construction of the dam. The photographs also depict construction of the dam, surveyors working in Black Canyon and on the Colorado River, and buildings in Boulder City. The photographs also depict Williamsville, the small settlement that preceded Boulder City.

Materials depict the Union Pacific Railroad Company's railroad tracks that had been damaged during floods in February and March of 1938 in Southern California and Southern Nevada, including by the Los Angeles Flood of 1938. The photographs primarily depict washed out tracks, damaged bridges, and debris.