This river's largest tributary, which flows through Hell's Canyon, is the Snake.
Features along the upper section of this river include Kinbasket Lake and the cities of Golden and Invermere. The Potholes Reservoir is located in this river's basin. Lake Umatilla is formed in this river by the John Day Dam, which lies just east of The Dalles. One of this river's tributaries is called the "Mult-no-mah River" on William Clark's map of the Lewis and Clark expedition, though that tributary is today known as the Willamette. This river's largest tributary, which flows through Hell's Canyon, is the Snake. For 10 points, name this river which flows into the Pacific Ocean in the northwest United States and forms the western part of the boundary between Washington and Oregon.
Features along the upper section of this river include Kinbasket Lake and the cities of Golden and Invermere.
{Columbia} River