Flows S into Thompson River, N of Kamloops
50.6819 N 120.3411 W — Map 092I09 — Google — GeoHack
Earliest known reference to this name is 1875 (Pemberton)
Name officially adopted in 1925
Official in BC – Canada
John Arrowsmith’s map BC 1859
Trutch’s map of BC 1871
George Monro Grant’s map of Yellowhead Pass 1872
Tolmie and Dawson map Indian Tribes of BC 1884
Zillmer maps of Cariboo 1939-1948 
Identified as North River in Canada Gazette, 14 October 1865. Subsequently designated North Branch of Thompson River; labelled “Thompson River, North Branch” on Pemberton’s 1871 map of British Columbia.— BC Geographical Names
Identified as “North River” on the reduced copy of a map referred to in the 16 July 1861 dispatch of James Douglas, first Governor of the Colony of British Columbia, and also in Canada Gazette, 14 October 1865. Subsequently designated “North Branch of Thompson River.” The name appears as “Thompson River North Branch” on the 1859 Arrowsmith map and as “North Branch of Thompson” on the 1871 Trutch map.
I have been unable to find the Joseph Despard Pemberton 1871 map of British Columbia.
- Arrowsmith, John [1790–1873]. “British Columbia, reduced copy of the map referred to in the despatch of Governor Douglas of 16 July 1861.” (1861). University of Victoria
- 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. North Thompson River