The Windust Caves are a series of nine caves that have been eroded into the side of a basalt cliff on the north side of the lower Snake River. The caves were excavated from 1959 until 1961 by a crew led by Harvey S. Rice. Some of the caves had been disturbed, though also somewhat preserved from looting by collectors, by rock falling off the roofs of the caves during construction of the Northern Pacific Railway. Other caves were damaged by collectors. In 1961, upon completion of the Ice Harbor Lock and Dam, the caves were flooded by the reservoir known as Lake Sacajawea.