Great Rift

The Great Rift is a 62 mile-long system of fractures in the Earth's crust and one of the few exposed volcanic rift systems in the world. The Rift runs northwest to southeast across almost the entire eastern part of the Snake River Plain. The Plain is a basalt bed several thousand feet deep, composed of numerous lava flows during the last few million years. The flows erupted from fissure or vent volcanoes located along north-south faultlines. It is the longest rift system in the Unitetd States and is designated a National Natural Landmark.