upon realizing the extent and importance of the site, they contacted the smithsonian institution, which conducted three seasons (1956–1958) of archeological digs in cooperation with the national geographic society. they reached a depth of more than 32 feet (9.8 m). an additional excavation was performed in 1962 by the national park service to a depth of 10.5 feet (3.2 m). this final excavation completed the archeological record and established an on-site exhibit.