The river is in the Lake Huron drainage basin and was named after Charles Rankin, who first surveyed the Bruce Peninsula.

The river heads south to Boat Lake where it receives the left tributary Clavering Creek at Jordan Bay.

In addition to the Rankin River drainage basin lying in the town of South Bruce Peninsula in Bruce County, portions of the tributary Clavering Creek drainage basin lie in Georgian Bluffs in Grey County.

During the 18th century, this river was part of a portage from Georgian Bay across the Bruce Peninsula used by fur traders.

[2] The river hosts fish species such as bass, Bowfin, northern pike, pickerel and perch, as well as trout and salmon during their spawning seasons.