A couple of the springs that arbitrarily flow out of the canyon walls down into the Snake River. The Snake River at Twin Falls, Idaho, cuts a dramatic 500-foot deep canyon. The 1,078-mile Snake River, the largest tributary of the Columbia River, flows from Wyoming through Idaho and Washington, forming the Idaho-Oregon border along North America’s deepest river gorge, Hells Canyon (over 1.6 km deep). It is defined by its dramatic volcanic landscape, essential irrigation, and indigenous history.