Geology of the Snake River Plain
Big Southern Butte
Goodale or Jeffrey's Cutoff
Toponce Stage Line and Root Hog
Idaho National Engineering & Environmental Laboratory
Snake River Plain Aquifer
Big Lost River Playas
Lost River Range and the Big Lost River Valley
Craters of the Moon
|Morning commuter buses approaching CFA (central Facilities Area) at the Idaho National Engineering Laboratory, 7 a.m., September 15, 1992. East and Middle Buttes rise out of the sagebrush desert in the background. View looks east.|
Idaho and Federal Dollars
Map of the east-central Snake River Plain.
of the Snake River Plain
The Snake River Plain contains Pleistocene basalt and interbedded sediment in the upper few hundred feet. The Snake River Plain Aquifer, the key to southern Idaho's agricultural economy, mainly consists of basalts and interbedded sediments, deposited in Pleistocene time (the last 2 million years). The underlying rhyolite does not seem to be a major aquifer because many of the pore spaces are filled with chemical precipitates. Within basalts, permeable zones are mainly the tops and bottoms of lava flows, with columnar jointing providing vertical transmission of water.