The James Cashman Sr. Photograph Collection (approximately 1905 to 1975) consists of black-and-white photographic prints, negatives, slides, and albums as well as a glass plate negative. The photographs depict four major subjects: Cashman's family, friends, and associates; Cashman's businesses; the Hoover Dam and Colorado River; and various locations across Nevada.

The collection is comprised of records of the San Pedro, Los Angeles & Salt Lake Railroad Company (1901-1976). The construction of this railroad led to the founding of Las Vegas, Nevada and the creation of the Empire Construction Company and Las Vegas Land and Water Company. The records document the company's operations and include correspondence and contracts relating to lots in the Las Vegas townsite, payments and accounts, invoices and other audit materials from 1905 to 1923. The collection also includes the records of the railroad agent at Arden Station, located ten miles south of the Las Vegas Station, which contain correspondence, ledgers, freight and way bills, shipping orders, and telegrams.