The seat of Sanders County, Thompson Falls has about 1,350 friendly residents. Rich in history, and preserving their local heritage, the city has many historic sites and buildings to explore. Stretching along the north side of the Clark Fork River, immediately opposite the Thompson Falls Dam and hydro station, Thompson Falls seems a somewhat sleepy little town content to bask in the natural beauty of the falls, the river and the mountains which surround it.
Though the county was founded in 1905 the courthouse is substantially younger, built in 1946. The Architect was Corwin & Co., the general contractor Frederick A. Long. The
First Courthouse was a large two story wood frame building adjacent to the the smaller brick jail, both built in 1907. The present courthouse is the site of the Sanders District Court and the Clerk of District Court, the official keeper of all District Court records for Sanders County. The building also houses the Motor Vehicles Department offices, the Sheriff’s Office, the Commissioner's Office, the County Attorney, the County Extension Office and other related offices.
Originally just Thompson, Thompson Falls was named in honor of fur trapper David Thompson, one of the best known explorers in the Northwest, the first person of European descent to enter many areas. A Canadian in the employ of the British North West Company, it was his job to establish trading posts for the purpose of obtaining furs for the company by trading with the natives. In 1809 he established
Saleesh House, the second trading post to be constructed in what is now Montana, about five miles east of here near the confluence of the Thompson and Clark Fork Rivers.
Though the railroad arrived in 1881 and a town site was platted in 1885, it was not until 1910 that the town of Thompson Falls was established. When gold was discovered in the nearby Cœur d'Alene area in 1883, Thompson Falls grew as a supply post, but it was the construction of the
Thompson Falls Dam, beginning in 1911, which supplied the town with a substantial economic base.