River Plain- Treasure Valley General Description
The Treasure Valley, which
includes the lower Boise River basin and extends south to the Snake River is located
within the northwest-trending topographic depression known as the western Snake
River Plain. The western Snake River Plain is a relatively flat lowland separating
Cretaceous-age granitic mountains of west-central Idaho from the granitic/volcanic
Owhyee mountains in southwestern Idaho. The western Snake River Plain extends
from about Twin Falls, Idaho northwestward to Vale, Oregon. The Snake River Plain
is about 30 miles wide in the section containing the lower Boise River. The depression
is believed to have been formed by crustal extension, beginning as early as 17
million years ago (Malde, 1991).
For geologic information
on the Treasure Valley click on the following links:
Original content compiled
by Christian Petrich, Margie Wilkins, Tondee Clark, and Tony Morse.
Photo provided by Idaho Department of Water Resources
Adaptation for the Digital Atlas of Idaho by Ean Harker- design/html, Kyle Raverty-
Information supplied by the Idaho Department of Water Resources; 1301 North
Orchard Street Boise, Idaho 83706 (208) 327-7900.