Walla Walla River

The Walla Walla River is a tributary of the Columbia River which runs through portions of eastern Washington and Oregon in the United States. Originating in the Blue Mountains, its two forks merge south of the town of Milton-Freewater, before continuing north into a wide river valley and floodplains as it approaches the Washington border. It receives Mill Creek as a tributary near the city of Walla Walla, alongside various anabranches formed by distributary channels which split off from the Walla Walla and rejoin it later on. It flows west and receives the Touchet River later in its course,...