The manuscript collections include papers of individuals and families and records of businesses, organizations, and churches, and document the rich and diverse history and culture of the Big Bend. Subject areas include government, society, law enforcement, ranching, the US-Mexico border, and the environment. Processed collections include the papers of Clifford B. Casey, E. E. Townsend, Roy W. Aldrich, Gene Hendryx, Harry Warren, the West Texas Historical and Scientific Society, and Big Bend National Park Land Acquisition.

The estimated 35,000 photographic images include single items, small and large collections of families, businesses, and organizations and the archives of Peter Koch, Charles M. Hunter, Glen Burgess, Charles W. Livingston, and W. H. Wilbourn. Other photographers represented in the holdings include W. D. Smithers, Frank Duncan, Mr. and Mrs. Carl Thain, and Thomas V. Skaggs.

The over 400 cataloged maps are predominately of Texas. The evolution of the State of Texas as part of Mexico and New Spain from the early 1700s to the present is documented. Hand-drawn maps record the formation of ranch holdings of A. S. Gage and others. Included are maps of Brewster, Jeff Davis, and Presidio counties and the City of Alpine, as well as topographic and highway maps. The Allen Realty Map Collection focuses on the City of Alpine and environs and although not cataloged is available for use.

Files documenting the history of the institution and campus, faculty and staff, outstanding students and alumni, clubs and organizations, sports, the National Intercollegiate Rodeo Association, Executive Committee minutes and academic departments make up the Sul Ross State University Archive. Formats include photographs and films, newsletters, and a variety of printed material and ephemera. Publications include the University newspaper The Skyline, yearbook The Brand, The Rossonian, El Ganadero, and others. The News and Publications Photograph Archive documents the campus, activities, students, and faculty from 1972-2006.

The Oral History Collection consists of recorded interviews primarily of area residents documenting personal experiences, knowledge, and history of the region. Descriptions of 128 interviews are cataloged with information about subjects and the availability of transcriptions and abstracts. Listening cassettes are available in the reading room.

The approximately 5,000 books held by the Archives include the core Texana and Roy W. Aldrich collections. Other subject areas are Archaeology, the description and history of the Southwestern United States, regional literature, and the Civil War. A portion of the closed stacks of the Library is held as well as Sul Ross State University student theses. The Archives collects local, regional, and Texas history.

The Archives serves as the repository for the most complete run of extant copies of The Alpine Avalanche and other regional titles. Paper copies in fragile condition are restricted with access provided via microfilm or in some cases digitally.

A growing collection (currently approximately 500) of vertical files contain clippings, printed, and other material referencing the scope of the contents of the Archives holdings and the collection area.