Flows W from Kamloops, then S and W into Fraser River at Lytton
50°14’07” N 121°34’57 W — Map 92I/4 — Google — GeoHack
Earliest known reference to this name is 1808.
Name officially adopted in 1925. Official in BC — Canada
The Thompson River proper starts at the confluence of the North Thompson River and the South Thompson River at Kamloops.
Thompson, a charity pupil at Grey Coat School, London, was apprenticed to the Hudson’s Bay Company in 1784. He joined the North West Company as a surveyor in 1797. In 1811 he explored the length of Columbia River, crossing the Continental Divide via the Athabasca Pass.
He was a member of the British-American Boundary survey, 1815-24. Thompson died of poverty at Longuineil, Quebec, in 1857, age 87
Thompson himself was never on any of the three Thompson Rivers.
- Fraser, Simon [1776–1862]. The letters and journals of Simon Fraser, 1806-1808. Edited by Lamb, W. Kaye. Toronto: MacMillan, 1960. Internet Archive
- Arrowsmith, John [1790–1873]. Provinces of British Columbia and Vancouver Island; with portions of the United States and Hudson’s Bay Territories. 1859. UVic
- Trutch, Joseph William [1826–1904]. Map of British Columbia to the 56th Parallel North Latitude. Victoria, B.C.: Lands and Works Office, 1871. University of Victoria
- British Columbia Geographical Names. Government of BC. Thompson River. BCGN