Glaciers at the head of the Blackwater (McKale) occasionally drop a chunk of graphite into the river. The water near the head of the river can be as black as ink, according to Everett Monroe.

There is a tributary of the Fraser River downstream from Prince George also known as the Blackwater: West Road (Blackwater) River. Blackwater in this case is a translation of the traditional name, derived from early native recognition that its many tributaries collect water from swamps and muskeg on the plateau, imparting a dye which stains the riverbed black (“Blackwater River”, by W.Hillen, Toronto, 1971). “West Road” was the name given by Alexander Mackenzie in 1793. The feature is labelled “Black or West Road River” on Trutch’s 1871 map and labelled “Blackwater or West Road River” on Dawson’s 1875 geological map of British Columbia between the Fraser River and the Coast Range.