The 2022 Addition (1985-2013) contains the personal correspondence of Walter Barbuck primarily directed to Nevada Senators, Congressmen, and other U.S. agency officials regarding proposed legislation impacting the environment. This series also contains publications and newsletters regarding environmental issues; a draft and final environmental impact statement for Groom Mountain Range, Lincoln County, Nevada; publications from partner organizations like the Bureau of Land Management (BLM) and the National Sierra Club; and records from the Toiyabe Chapter of the Sierra Club from 1998 to 2007.

The Caddo Company, Incorporated series (1922-1965) is comprised of twelve sub-series containing film production and corporate records.

The first two sub-series contain materials related to two films that predate the formation of The Caddo Company, Incorporated as a production company, Swell Hogan (1926) and Everybody's Acting (1926), financed by Howard Hughes. The remaining sub-series represent the nine films produced under the Caddo banner and general corporate records.

Materials within each film sub-series include advertising and publicity, administrative, censorship, distribution, editing, financial, legal, and production and direction records, as well as film soundtracks and screenplays. Types of materials include of ledgers, correspondence, storyboard images, sheet music, and original scores, as well as film, direction, set, and production stills. Corporate records consist of newspaper clippings, administrative correspondence, actor and distribution contracts, and financial reports.