The Columbia River Basalt Group (including the Steen and Picture Gorge basalts) extends over portions of five states. Victor Camp and Martin Ross, via WikiCommons

Geology 101: Idaho and Vulcanism


Idaho, especially the southern two-thirds of the state, is a poster child for the effects of volcanoes on a landscape. For the last 17 million years or so, pretty much everything volcanoes can do to the countryside has been done to WC’s new home state.1 Up until about 17 million years ago, more or less,…