Snake River Plain

The Snake River Plain is a geologic feature located primarily within the U.S. state of Idaho.

The western plain began to form around 11–12 Ma (million years ago) with the eruption of rhyolite lavas and ignimbrites.

Its morphology is similar to other volcanic plateaus such as the Chilcotin Group in south-central British Columbia, Canada.

The eastern plain is a topographic depression that cuts across Basin and Range mountain structures, more or less parallel to North American Plate motion.

Younger volcanoes that erupted after passing over the hotspot covered the plain with young basalt lava flows in places, including Craters of the Moon National Monument.

Current climatic conditions began to characterize the region in the early Pleistocene (approximately 2.5 million years ago).