The Elizabeth von Till and Claude N. Warren Professional Papers (1916-2021) are comprised of the personal and professional papers of anthropologist Claude N. Warren and historical preservationist Elizabth von Till Warren. The materials in this collection primarily consist of research files, maps, and drawings on various archaeological and historical preservation projects in southern Nevada of which they both were involved. This collection includes field notes and surveys from archaeological projects such as the Old Las Vegas Mormon Fort and the Las Vegas Springs Preserve. Records on von Till Warren's involvement with the Old Spanish Trail Association, Southern Nevada Historical Society, and historic preservation work around southern Nevada are represented. Also included are Robert H. Crabtree's archaeological research files, a colleague of Claude Warren who bequeathed his professional files to him upon his death.