Gatecliff Rockshelter (26NY301) is a major archaeological site in the Great Basin area of the western United States that provides remarkable stratigraphy; it has been called the "deepest archaeological rock shelter in the Americas". Located in Mill Canyon of the Toquima Range in the Monitor Valley of central Nevada, Gatecliff Rockshelter has an elevation of . David Hurst Thomas discovered Gatecliff Rockshelter in 1970 and began excavations in 1971. Full scale excavations occurred at Gatecliff Rockshelter for about seven field seasons in which nearly of sediments were exposed for a well-defined stratigraphic sequence. The well-preserved artifacts and undisturbed sediments at Gatecliff Rockshelter provides data and information have been applied to a range of research topics. Based on the analysis of the artifacts at Gatecliff Rockshelter, it can be determined that it was most likely a short-term field camp throughout prehistory. The latest evidence for human usage at Gatecliff occurs between ca. 5500 B.P. to 1250 B.P. In August 1974, a short-film was created: Gatecliff: American Indian Rock-Shelter. In April 1979, Gatecliff Rockshelter was listed in the National Register of Historic Places. Discovery David Hurst Thomas discovered Gatecliff Rockshelter in June 1970 following his first field season in the Reese River Valley and ancient Lake Tonopah. Thomas also conducted systematic settlement surveys of the Monitor Valley in Central Nevada in efforts to study prehistoric ecology, subsistence patterns, and chronological sequences of the Great Basin. After a day of excavation, Thomas and his crew stopped by a local diner. At the dinner, Thomas spoke with the waitress's husband, Gale Peer, a mining geologist with over 40 years of experience in the Great Basin. Peer gave the crew of archaeologists a few general directions to an interesting cave with possible rock art. The following year, Thomas returned and attempted to search for this cave. After searching through nearly 15 canyons in the area, driving through and getting out of the car to physically check the caves and rock shelters, Thomas ended at the Mill Canyon. At the opening of the rock shelter, Thomas observed pictographs but no visual artifacts. The paintings were human figures in red and yellow as well as cryptic motifs in black and white on the ceiling and rear wall. Thomas then dug a deep test pit to ensure the potential of the site. The test pit revealed sub-surface deposits and incised stones with some burned bones. Given the potential