The Thomas Clark Professional Papers (1950-1998) contain materials from his tenure as a Professor of English at the University of Nevada, Las Vegas (UNLV), which are divided into two series. The gaming research series includes newspaper clippings, correspondence, brochures, bulletins and articles. Also included are book chapters, a glossary of terms used in the casino industry, and gambling guides. In the linguistics and teaching series there are research files, articles, speeches, correspondence, interviews, multimedia, workshops, and conference materials. Also included are files on graffiti, symbolism, ethnic and regional speech differences, language usage, and National Council of Teachers of English (NCTE) material. Additional materials include colleague publications and cassette tapes of interviews from students in courses Clark taught at UNLV.

Oral history interview with D. L. Newell conducted by Paula Sue Curry on February 26, 1977 for the Ralph Roske Oral History Project on Early Las Vegas. In this interview, Newell describes life in Henderson, Nevada during the 1950s and how the city has changed. Newell discusses the companies that established chemical and metal plants in Henderson, how the growth of Las Vegas, Nevada affected Henderson, and the history of gambling in Southern Nevada. He also talks about mining, medical care available in Henderson, local celebrations, and pollution caused by chemical and metal plants.

Oral history interview with Cleona Sorenson and Theona Ohlson conducted by Fred F. Aldrich on March 04, 1977 for the Ralph Roske Oral History Project on Early Las Vegas. In this interview, Cleona and Theona discuss growing up in Mesquite, Nevada and later moving to Las Vegas, Nevada. The two then describe life during World War II, the increase of tourism in southern Nevada, and the significance gambling has to the growth of the Las Vegas economy.