The river was named after an engineer on one of the Canadian Pacific Railway surveys in the 1870s.

[1] The McLennan River originates in the Premier Range, flowing from McLennan Glacier between Mount Stanley Baldwin and Mount Arthur Meighen.

Then it turns northwest, flowing through the Rocky Mountain Trench, picking up tributary streams flowing from the Selwyn Range to the east and the Premier Range to the west.

It joins the Fraser River at Tête Jaune Cache.

This article related to a river in British Columbia, Canada is a stub.