The Yucca Mountain Environmental Safety Collection (1970-2011) consists of reports and impact studies collected by Clark County's Nuclear Waste Division library for documenting Yucca Mountain's potential health and safety risks to Southern Nevada. The reports contain documents pertaining to potential environmental, health, financial, and safety risks from the Yucca Mountain Nuclear Waste Repository, which is located in Nye County, Nevada. The collection contains scientific and social studies in support of and opposition to the site. The bulk of the collection includes licensing reports, site selection studies, and impact studies from transporting, storing, and handling radioactive waste and spent nuclear fuel.

The collection is comprised of architectural drawings (1952-1997) completed by American architect, Ethan Jennings Jr. and/or his architectural firm, Ethan Jennings Jr., AIA, CSI and includes Jenning's work from the firm of John Badgley, AIA, where Ethan Jennings Jr. worked in Southern California during the 1950s, as well as work Jenning's completed with Americo Inc., and Tolosa Group. The collection contains 217 sets of drawings, 6 boxes of project records, and 8 flat files of oversized material from over 200 different projects primarily located in California with some projects located in the Las Vegas area. The materials feature hand-drawn architectural drawings, ranging from preliminary sketches to construction documents. The drawings also contain work from consultants, engineers, and other architects who collaborated on the development of the various projects. The drawings include: commercial, industrial, professional, civic, residential, and religious buildings of varying scales, such as libraries, apartments, warehouses, office developments, schools, military buildings, churches, and custom single-family homes located throughout California and Las Vegas. The drawings also include a number of additions, remodels, and renovations. The collection also contains project records like structural calculations and drawings, project manuals and specifications, bid documents, and professional correspondence.

The Chester Longwell Photograph Collection consists of 608 black-and-white photographic prints dating from approximately 1910 to 1930. The images primarily depict the Longwell family's excursions in the Southern Nevada region, primarily to Mount Charleston, Nevada. Also included are images of Southern Nevada mines and mining towns, as well as Pubelo Grande de Nevada, the Lost City. The remaining images depict geological formations and features, as well as forestry and nature scenes in Nevada and Arizona.