Snake River is the chief branch of the Columbia River. The Snake River rises in Wyoming near the Continental Divide in Yellowstone National Park. The river then flows south through Grand Teton National Park. It bends west and flows across the Snake River Plains of southern Idaho. Irrigation projects, dams, and falls provide water for power and irrigation for the cities and farms located on the plains.
The Snake River turns north at the Oregon border. The river forms part of the boundary between Idaho and Oregon and flows through Hells Canyon. At Lewiston, Idaho, the Snake turns west and flows through southeastern Washington. Boats can use the Columbia and Snake rivers from the Pacific Ocean inland to Lewiston. Lewiston and nearby Clarkston, Washington, are important ports for grain and wood products exports. The Snake River joins the Columbia River near Pasco, Washington, 1,038 miles (1,670 kilometers) from its source.
