David Thompson

The river below is the one Thompson scouted first. On September 27, 1809, he left Kullyspel House on Lake Pend Oreille with a voyageur named Beaulieu and a Kalispel boy to explore the stream flowing west out of the lake, which he called the Saleesh River. They rode along it past the wide marsh near present Cusick, then canoed downriver for two days to Box Canyon above Metaline Falls, now flooded behind Box Canyon Dam, and turned back, reaching Kullyspel House again on October 6.

What the plaque says

David Thompson 1770 - 1857 In the historic race between British and American fur traders for control of Columbia River trading, David Thompson, a partner of North West Company, was first to travel the Columbia from source to mouth. Energetic explorer, surveyor and mapper, he founded Kootenay House in Canada, the first trading post on the Columbia, in 1807, Spokane House in 1810, and first mapped the Pend Oreille, Snake, and other rivers in the Columbia Basin, claiming the entire region for Great Britain

Where it stands