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.

The Martha C. Knack and Omer C. Stewart Research Papers on the Pyramid Lake Paiute Tribe contains materials collected by Stewart and Knack as research for their 1984 book, As Long as the River Shall Run: An Ethnohistory of Pyramid Lake Indian Reservation. The collection focuses on the Pyramid Lake Paiute Reservation in Northeastern Nevada from 1845 to 1975 and include letters, journal articles, legal documents, government documents, treatises, and records. All materials are photocopies of documents that date between approximately 1845 to 1980.