Snake River

The Snake is a major river of the greater Pacific Northwest in the United States. At 1,078 miles (1,735 km) 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 (1,500 m3/s). 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.

Snake River in Supervolcano
During one of Kelly Birnbaum's geology undergraduate lectures at Cal State Dominguez Hills, she talked about the Yellowstone Supervolcano hotspot and how its location shifted as the North American tectonic plate slid. It had started under northeastern Oregon 17-18 million years ago, moved across Idaho and ended up under Yellowstone National Park, erupting every so often at a slightly different location. The shape of the Snake River Valley followed the path of these eruptions fairly closely.