The Snake River is a major tributary of the Columbia River, besides being on its own one of the largest rivers in the United States. It delivers an average of 50,000 cubic feet of water into the Columbia every second, about 1/5 of the Columbia's total flow.
From its origin in Yellowstone National Park, the Snake flows some 1,000 miles before joining the Columbia. This includes Hells Canyon, the deepest river gorge in earth at 7,900 feet.
The Snake River flows through an area of SE Washington known as the Channeled Scablands. Remnants of prehistoric humans are found throughout the basin. An ancient rock shelter once occupied by "Marmes Man" is one of the oldest inhabited sites in the U.S.