Structural and Stratigraphic Significance of the Snake River Capture, Idaho-Oregon

Abstract

Lindgren (1898b) believed that the waters of the Snake River between Idaho and Oregon were impounded by Columbia River lavas to create a great late Tertiary lake in southwestern Idaho. Livingston (1928) concluded that late Tertiary deformation interrupted a postulated former Snake course through northeastern Oregon and that the resulting lake spilled into the headwaters of one of its downstream tributaries, thus creating the present river course. On evidence from the lower Snake in Washington, Lupher and Warren (1942) suggested that the upper Snake may have belonged to a different drainage system in preearly Pleistocene time. On the basis of the youthfulness of the Snake River Canyon, the barbed tributaries in its upper part, and other physiographic and structural evidence, together with correlation of these features with portions of the late Tertiary-Quarternary stratigraphic record, it is concluded that: (1) although Livingston's evidence is invalid, the capture or spillover is a fact; (2) the capture o...