The Union Pacific Railroad Company series (1899-1974) contains photographs, maps, plans, drawings, and instruction books pertaining to the operation of the Union Pacific railroad.

The Law Department series (1865-1983) contains the files kept by the legal department in Los Angeles, California, which made all final decisions regarding legal matters for the Union Pacific and the Las Vegas Land & Water Company. The legal department reviewed all matters which had legal implications for the railroad at local, state, and federal level, and drafted and reviewed all legal documents and transactions, including contracts, claims, employee relations, rates, court cases and judgements, land acquisitions and sale, abstracts of title, station closings, state and federal legislation, filings and proof of construction, passes, patents, payroll, permits, bond issues, taxes, and uncollected accounts. They also reviewed anything affecting the railroad company’s water rights and water supply, as well as all matters that appeared before the Interstate Commerce Commission.

The Chief Engineer and Engineering Files series (1903-1972) contains materials relating to the Chief Engineers office in Los Angeles, California. The chief engineers office was responsible for all railroad construction, including track, sidings, stations, depots, and all railroad and railroad-owned buildings. The chief engineer laid out the company townsites in Las Vegas, Nevada and designed the depots. The Engineering Department was also responsible for the construction of all water facilities and pipelines in Las Vegas, as well as any other towns in which the railroad owned the water supply. The local engineer in Las Vegas reported to the Chief Engineer in Los Angeles. During World War II, the engineers office was responsible for protecting critical railroad installations for which there is a series of files titled “War Conditions."

The Real Estate series (1905-1974) contains files that document easements, encroachments, and crossings throughout Nevada.