Fort Walla Walla, a fur-trading post built by the North West Company in 1818 on the left bank of the Columbia river, at the mouth of the Walla Walla river. It was taken over by the Hudson's Bay Company in 1821, was rebuilt in 1841, and remained in operation until the Hudson's Bay Company had to surrender their posts in the Oregon country. It was sometimes called Fort Nez-Percés.

Source : W. Stewart WALLACE, ed., The Encyclopedia of Canada, Vol. II, Toronto, University Associates of Canada, 1948, 411p., p. 378.