The C. L. Sonnichsen Special Collections Department is located on the sixth floor. The book collections include the Chicano Collection, the Judaica Collection, the S. L. A. Marshall Military History Collection, the Southwest and Border Studies Collection, as well as collections of art and rare books. In addition to printed sources, the department has almost 800 manuscript and archival collections. There is also an oral history collection documenting the region.
The department is named after longtime English professor and historian C.L. Sonnichsen (1901 – 1991). Dr. Sonnichsen taught at UTEP for 41 years and wrote over 30 books – mainly histories of the southwestern United States.