Adopted in the 11th Report of the Geographic Board of Canada, 20 June 1912, as the well-established name.

Source: BC place name cards, or correspondence to/from BC's Chief Geographer or BC Geographical Names Office

On Turnor map, 1790, as "Beaver Indian river by the Canadians called the Peace River" (18th Report of the Geographic Board of Canada, 31 March 1924). Identified as "Unjigah or Peace River" in Alexander Mackenzie's journal (Voyage to the Pacific... 1793 p.319). Identified as "the great Unjigah or Peace River" by G.M. Dawson (Geological Survey Report 1879-80, p51B).

Source: BC place name cards, or correspondence to/from BC's Chief Geographer or BC Geographical Names Office

"....we came to the Peace Point [near Lake Athabasca in NE Alberta] from which, according to the report of my interpreter, the river derives its name. It was the spot where the Kristeneaux [Cree] and Beaver Indians settled their dispute. The real name of the river and point being that of the land which was the object of contention. When this country was formerly invaded by the Knisteneaux, they found the Beaver Indians inhabiting the land about Portage la Loche; and the adjoining tribe were those whom they called Slavey. They drove both these tribes before them; when the latter proceeded down the river from the Lake of the Hills [Lake Athabasca], in consequence of which that part of it obtained the name of the Slave River. The former proceeded up the river, and when the Kristeneaux made peace with them, this place was settled to be the boundary." (Alexander Mackenzie, Voyage to the Pacific... 1793, partially reprinted in the 18th Report of the Geographic Board of Canada, 31 March 1924.)

Source: BC place name cards, or correspondence to/from BC's Chief Geographer or BC Geographical Names Office

Peter Pond's maps of 1785 and 1787 refer to it as the "River of Peace". Other names have included Un-ja-ga/Unjigah, as recorded on a map to accompany Mackenzie's "Voyage to the Pacific... 1793". It apparently means Large River in the Beaver language. In 1927, Father Morice, OMI, corroborates this translation by saying the Peace River was known to the Sekani Indians as Thû-tcî-Kah, or Water Great (or Important) River. Another source stated it was a translation of the Slavey word Chin-ch-ago, meaning Beautiful River. The Fort Chipewyan Hudson's Bay Company post journal of 1822 also refers to it as Rivière de Brochet, referring to the northern pike which were likely found in the river.

Source: Place Names of Alberta, Alberta Geographical Names Program and Friends of Geographical Names of Alberta Society, University of Calgary Press, 4 volumes, 1991-1996.

Peace River was known as the unijigah of which "peace" is the translation. The Sekani, who dwelt further up the river, knew it as isetaieka, "the river which runs by the rocks," a reference to its passage through the Rockies. (see "Peace River Was Old Indian Boundary Line" National Resources Canada, December 1927 clipping). Headwaters in British Columbia at 56º01' - 122º12' on map 94 B/1. Mouth in Alberta at 59º00' - 111º25' on map 74 L/14.

Source: Canadian Geographical Names Database, Ottawa