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.

The Land and Tax series (1891-1974) contains files for demountable houses in Las Vegas built between 1943 and 1961; company houses in Caliente, Nevada; leases and agreements; general correspondence, acquisitions, and “vacations” (when the company vacated properties); and land valuations.

The National War Industries Projects series (1942) contains five binders compiled by the Manager of Industrial Development that detail war projects in Missouri, Nebraska, Kansas, Colorado, Wyoming, Utah, Idaho, Oregon, Washington, Nevada, and California.

For each project in each corresponding state, there is a standard form listing the location, a description of area and improvements, cost of project, owner, operator of plant and railroads serving plant, and any affect on Union Pacific property or facilities, including whether new access track or other changes to facilities was required. Types of projects include processing, production, manufacturing, and assembly plants, supply depots, training camps and airfields, Japanese and alien internment camps, and prisoner of war camps. There is an index of projects by both state and type of plant.

The Bound Legal Briefs series (1913) is comprised of sixty-one volumes of legal cases filed in the California Judicial District by the Union Pacific Railroad Law Department.

The Walter Bracken and the Las Vegas, Nevada office sub-series (1828-1968) is comprised of information related to the development of Las Vegas, Nevada and Yermo, California, including land and water purchases and sales, company cottage leases, accounting, Board of Directors meetings, the Las Vegas Ranch and other documentation.