Columbia River Basalt Group
- Lewiston Basin Field Trip (idahogeology.org)
Lewiston, Idaho, and Clarkston, Washington, are at the confluence of the Snake and Clearwater rivers in the Lewiston basin. Hells Canyon stretches to the south of Lewiston on the Snake River. This is the lowest point in Idaho at 720 feet (220 m) elevation. Lewiston is Idaho’s seaport, a result of slack water created by several dams and locks on the Columbia- Snake River system.
- Snake River (Wikipedia)
The Snake River is a major river in the interior Pacific Northwest region of the United States. About 1,080 miles (1,740 km) long, it is the largest tributary of the Columbia River, which is the largest North American river that empties into the Pacific Ocean. Beginning in Yellowstone National Park, western Wyoming, it flows across the arid Snake River Plain of southern Idaho, the rugged Hells Canyon on the borders of Idaho, Oregon and Washington, and finally the rolling Palouse Hills of southeast Washington. It joins the Columbia River just downstream from the Tri-Cities, Washington, in the southern Columbia Basin.
