The Main Channel Dam was built just above the original falls, a 30 foot high cascade in the Clark Fork River. Thompson Falls, the falls and the city of the same name, were named after Canadian explorer, surveyor, justice of the peace, businessman, author and fur trader
David Thompson, who built
Kullyspell House, the first fur trading post in the American Northwest.
The falls themselves are still there, cascading as they have for about 10,000 years, now supplemented by manmade waterfalls from the dam. The waterfall is almost seasonal, as the flow in the fall and winter can become a trickle in some years.
Coordinates given are for the best viewing location, at an observation point at the northwestern end of the Main Channel Dam. One must park on the north side of the river, walk over the old vehicle, now pedestrian, bridge and follow the path down to the observation point.