The sections near its mouth around Fort Stevens and its namesake Bar are still especially treacherous to navigate.
Tributaries of this river include the Umatilla, the Incomappleux, and the Goldstream River, and minor towns on it include Boardman, Cascade Locks and Pateros. The sections near its mouth around Fort Stevens and its namesake Bar are still especially treacherous to navigate. Due to significant manmade alteration of the river, it is open to navigation all the way to Clarkston, leaving as the last free-flowing portion a fifty-one mile reach around the Hanford Nuclear Reservation. Massive Ice Age floods, caused by the breaking of an ice dam near Missoula, carved its namesake Gorge and the nearby Grand Coulee. For 10 points, name this heavily dammed largest river of the Pacific Northwest.
Tributaries of this river include the Umatilla, the Incomappleux, and the Goldstream River, and minor towns on it include Boardman, Cascade Locks and Pateros.
{Columbia} River