The Elizabeth von Till and Claude N. Warren Professional Papers (1916-2021) are comprised of the personal and professional papers of anthropologist Claude N. Warren and historical preservationist Elizabth von Till Warren. The materials in this collection primarily consist of research files, maps, and drawings on various archaeological and historical preservation projects in southern Nevada of which they both were involved. This collection includes field notes and surveys from archaeological projects such as the Old Las Vegas Mormon Fort and the Las Vegas Springs Preserve. Records on von Till Warren's involvement with the Old Spanish Trail Association, Southern Nevada Historical Society, and historic preservation work around southern Nevada are represented. Also included are Robert H. Crabtree's archaeological research files, a colleague of Claude Warren who bequeathed his professional files to him upon his death.

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.