Archaeological Investigations at Site 45-OK-258, Chief Joseph Dam Project, Washington.

Abstract : Site 45-OK-258 is on the north bank of the Columbia River about 125 meters upstream from River Mile 576. Vegetation is characteristic of the Upper Sonoran life zone. We excavated 4,882.9 cubic meters of site volume in 1978 and 1979 as part of a mitigation program associated with adding 10 feet to the operating pool level behind Chief Joseph Dam. A two-stage sampling design, incorporating random and nonrandom 1 x 1 x .01 meter units of record, disclosed multiple episodes of prehistoric occupation spanning a period from about 3600 to about 100 years ago. Two major occupational components associated with 6 stratigraphically defined analytic zones are evident. The first component dates roughly between 3600 and 2400 years ago, and has 4 associated housepits. Assemblages associated with both the house floors and external surfaces suggest the site was a central base, a probable winter village, associated with the Hudnut Phase (4000 to 2000 B.P.). Faunal assemblages of this component contain a high percentage of carnivores; strong emphasis on consumption of fish is suggested by the high frequency of burned and broken salmonid vertebrae. The second component is dated from about 800 years ago to the modern era, and associated with the Coyote Creek Phase (2000 to 150 B.P.). It contains at least one housepit, and several occupation surfaces. It appears to represent a central base, but may have changed useages to a field camp within the occupation span. Horse remains indicate a protohistoric association late in the occupation. Archaeobotanical analysis is presented for both components, documenting the earliest known occurrence of a cache of the seeds of Chenopodium femontii (about 2800 B.P.) in the Plateau.