Geology Across and Under the Western Snake River Plain, Idaho: Owyhee Mountains to the Boise Foothills

By Spencer H. Wood
This trip traverses the Snake River Plain from the Owyhee front, south of Marsing, Idaho, to the Boise foothills, east of Boise, Idaho and addresses the history of Neogene Lake Idaho along the edges of the western Snake River Plain as recorded in the sedimentary record. The transgressional phase of the last filling of Lake Idaho is marked by an angular unconformity; in the Boise foothills stops are at localities of prodelta muds, Gilbert-deltas, and oolite beds, and finally at the Table Rock Quarries.
thumbnail image of Western and eastern Snake River Plain and late Cenozoic geologic features of the northwestern United States. (fig. 2)