The Thief River is a tributary of the Red Lake River in northwestern Minnesota. It originates in Marshall County and flows south, joining the Red Lake River at Thief River Falls. The Thief River is part of the larger Red River Basin watershed that drains north into Lake Winnipeg. Paddling opportunities on the Thief River itself are limited, but it contributes to excellent paddling on the Red Lake River after their confluence.

The most popular paddling section begins at the meeting of these rivers in Thief River Falls, offering an urban paddle through landscaped riverbanks and multiple public access points. This 2-3 mile stretch features Class I-II rapids, suitable for beginners and families. Below Thief River Falls, the Red Lake River provides several noteworthy paddling sections. The stretch from Smiley Bridge to Centennial Park offers 12.3 miles of calm flatwater, ideal for novice paddlers. For more experienced kayakers, the 13.5-mile section from Red Lake Falls to Sportsman Park presents Class II-III rapids with scattered boulders and riffles.

The best paddling season typically runs from late spring through early fall, with water levels and flow rates varying based on rainfall and snowmelt. The rivers wind through diverse landscapes, including the Red Lake Indian Reservation, offering unique cultural and natural scenery. Wildlife enthusiasts can spot a variety of birds along the Minnesota Pine to Prairie Birding Trail, which includes the Thief River area. The rivers support populations of walleye, northern pike, and catfish, making them popular for fishing as well.

Key access points include city parks in Thief River Falls, Smiley Bridge, Centennial Park, and Sportsman Park. These locations provide boat launches and often camping facilities for multi-day trips. The Thief River and Red Lake River played significant roles in the region's history, serving as transportation routes for Native Americans and early settlers. Today, they continue to be important for recreation and as a water source for local communities.

Paddlers should be aware of varying water conditions, especially in rapids sections. It's advisable to check current river levels and weather forecasts before embarking on any trip. Local outfitters in Thief River Falls and Red Lake Falls can provide up-to-date information and rental equipment. For those seeking longer adventures, it's possible to plan multi-day trips along the Red Lake River, with numerous access points and campgrounds available along its course. These extended journeys offer a comprehensive experience of the region's natural beauty and rich cultural heritage.