A photo of a roadside memorial

This view is from a roadside memorial that commemorates the upstream end of the natural navigable river (prior to construction of the dams) near the western end of the Columbia River Gorge near Portland. A roadside commemorative display is located at this site. Under the direction of the British Admiralty, Captain George Vancouver was sent to explore the Pacific Coast of North America. Vancouver sent a ship under command of William Broughton to explore the navigable extent of the Columbia River. The ship reached this point of the river in late October of 1792. The Lewis and Clark Expedition reached this point in late fall of 1805 (Lang, [2010]).