50°14’07” N 121°34’57 W — Map 92I/4 — Google
Earliest known reference to this name is 1808.
Name officially adopted in 1925. Official in BC — Canada
The source of the Thompson River is the junction of the North Thompson River and the South Thompson River, at Kamloops.
“Named in 1808 by Simon Fraser, North West Company, during his descent of the Fraser River to its mouth; after geographer David Thompson. A charity pupil at Grey Coat School, London, he was apprenticed to the Hudson’s Bay Company in 1784; joined the North West Company in 1797; explored the length of Columbia River, 1811; British-American Boundary survey, 1815-24. Died of poverty at Longuineil, Quebec, in 1857, age 87. Thompson himself was never on any of the three Thompson Rivers.”
The name appears on B.C. Surveyor General Joseph William Trutch’s 1871 “Map of British Columbia to the 56th Parallel North Latitude.”
- Fraser, Simon [1776–1862]. The letters and journals of Simon Fraser, 1806-1808. Toronto: MacMillan, 1960. Internet Archive
- 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