[1] The river issues from the west side of Rainy Lake (French: lac à la Pluie; Ojibwe: Gojiji-zaaga'igan) and flows generally west-northwest, between International Falls, Minnesota, and Fort Frances, Ontario, and between Baudette, Minnesota, and Rainy River, Ontario.

The drainage basin of the river stretches east to the height of land about 100 kilometres (62 mi) west of Lake Superior.

It was the southeast corner of the huge tract of land granted in 1670 by the English Crown to the Hudson's Bay Company.

A white sucker weighing 6lb 8oz caught on the Rainy River near Loman, Minnesota stands as the IGFA all tackle world record.

[4] American author Tim O'Brien's novel The Things They Carried (1990), set during the Vietnam War, includes a chapter, "On the Rainy River," referring to this territory.