Snake River

The Snake is a major river of the greater Pacific Northwest in the United States. At 1,078 miles long, it is the largest tributary of the Columbia River, the largest North American river that empties into the Pacific Ocean. Rising in western Wyoming, the river flows through the Snake River Plain then rugged Hells Canyon and the rolling Palouse Hills to reach its mouth at the Tri-Cities of the state of Washington. Its drainage basin encompasses parts of six U.S. states, and its average discharge is over 54,000 cubic feet per second. Rugged mountains divided by rolling plains characterize the physiographically diverse watershed of the Snake River. The Snake River Plain was created by a volcanic hotspot which now lies underneath Yellowstone National Park, the headwaters of the Snake River. Gigantic glacial-retreat flooding episodes that occurred during the previous Ice Age carved out many topographical features including various canyons and ridges along the middle and lower Snake. Two of these catastrophic flooding events significantly affected the river and its surrounds.