The Rainy River forms a significant portion of the border between Minnesota and Ontario, flowing westward for approximately 85 miles from Rainy Lake to Lake of the Woods. This historic waterway served as a vital transportation route for Indigenous peoples and later fur traders, earning it the nickname Voyageur's Highway. The river's main tributaries include the Little Fork River and Big Fork River, both joining from the Minnesota side. The Rainy River watershed covers about 14,500 square miles, draining parts of northern Minnesota and northwestern Ontario.

Paddling opportunities on the Rainy River range from flatwater lake paddling on Rainy Lake to more challenging upstream sections on the main river. The Rainy Lake and Rainy River Route offers a 255-mile journey from Voyageurs National Park to Lake of the Woods, allowing paddlers to retrace the historic voyageur route. This trip combines lake and river paddling, with potential upstream challenges on the river sections. The overall difficulty ranges from beginner-friendly flatwater on Rainy Lake to intermediate sections requiring more skill on the main river, especially when paddling upstream. Paddlers should be prepared for potential large waves on windy days, particularly on the lakes.

Late spring through early fall offers the best paddling conditions, with summer providing warmer temperatures but potentially more boat traffic. Fall colors can be spectacular but come with cooler temperatures. The river corridor supports diverse wildlife, including bald eagles, ospreys, moose, and various fish species. Walleye fishing is particularly popular.

Key landmarks include Voyageurs National Park, with its interconnected lakes and rich history, and the towns of International Falls, MN and Fort Frances, ON at the river's eastern end. The Rapid River, a major tributary, offers a scenic 33-mile canoe route with small riffles and Class I rapids.

Primary access points include the Voyageurs National Park Rainy Lake Visitor Center, various points along the Rainy River, and boat launches on Lake of the Woods. The towns of International Falls, Baudette, and Warroad provide services for paddlers.

Safety considerations include being prepared for sudden weather changes, large waves on open water, and increased boat traffic, especially near Lake of the Woods. Paddlers should carry appropriate safety gear and be aware of international border regulations.

Multi-day trip options abound, from exploring Voyageurs National Park's interconnected lakes to the full 255-mile Rainy Lake to Lake of the Woods route. Backcountry campsites in Voyageurs National Park and along the river provide overnight options for extended journeys.

The Rainy River system offers paddlers a unique blend of natural beauty, rich history, and diverse paddling experiences, making it a premier destination for canoeists and kayakers in the northern Minnesota region.