Gatecliff Rockshelter - Excavation

Excavation

After the initial discovery in 1970, Thomas and a crew from the University of California Davis began an extensive, large scale excavation. By the end of the first season, the crew had excavated a 7 meter long and 3 meter deep trench. Research continued in 1973 with the sponsorship of the American Museum of Natural History and Expeditions International. The excavations that year reached a depth of 4.8 meters and obtained radiocarbon dates of approximately 2500 B.C. In 1974, the American Museum of Natural History and Education Expeditions International again sponsored the excavations at of Gatecliff Rockshelter again. By the end of this season, the crew had excavated 98 cubic meters of deposits. Due to the danger of the steep and exposed sidewalls, the excavation strategy switched from vertical to horizontal. Starting in 1975, the excavators at Gatecliff removed stratigraphic layers one by one based on their natural levels. Natural levels were determined by the different strata in the deposits seen in the excavation profile. Horizontal strategies continued in 1976 in which the excavators ultimately removed deposits until reaching bedrock. Excavations were completed in late August 1978 with a depth of nearly 39 feet (12 m) and a total of 23,000 cubic feet (650 m3) of deposits removed.