The Two Medicine River originates at the Continental Divide in Glacier National Park, flowing approximately 60 miles eastward through northwestern Montana before joining Cut Bank Creek to form the Marias River, roughly 12 miles southeast of Cut Bank. This tributary system drains a 250-square-mile watershed as it descends from the Rocky Mountain Front, carving through the Badger-Two Medicine area—a wild, roadless expanse wedged between the Bob Marshall Wilderness and Glacier National Park—before crossing the Blackfeet Indian Reservation and continuing through Glacier and Pondera Counties.

The river offers diverse paddling opportunities ranging from technical whitewater to extended flatwater journeys. The Canyon section through the Badger-Two Medicine presents the most challenging water, rated Class III-IV, as it navigates remote terrain between wilderness boundaries. The longest established run spans 62 miles from the Forest Service Boundary to Sullivan Bridge, rated Class II-III, providing a substantial multi-day expedition through varied landscapes. The South Fork Two Medicine also features a canyon section for experienced paddlers, while a shorter stretch from north of East Glacier to East Glacier Bridge offers additional access points.

Spring runoff provides optimal flow conditions, typically from late May through early July, when snowmelt from Glacier National Park's peaks swells the river. The Two Medicine receives contributions from Birch Creek in southeastern Glacier County, adding volume as it progresses eastward. Summer flows diminish considerably, and the river's character transforms from pushy whitewater to technical maneuvering through shallow sections.

The watershed supports genetically pure westslope cutthroat trout populations, particularly in the cold, intact headwaters—some of the last remaining east of the Continental Divide. Grizzly bears frequent the riparian corridors, and moose tracks appear regularly along gravel bars in the upper reaches. The surrounding landscape transitions from glaciated peaks and scorched pine forests in the headwaters to rolling grasslands downstream.

Sullivan Bridge serves as a primary access point at the confluence with Cut Bank Creek, where the Bureau of Land Management maintains launch facilities with gravel road access amid sheer cliffs and riparian vegetation. The river flows past East Glacier Park, where Amtrak's Empire Builder crosses the waterway, providing a recognizable landmark. Upper sections require careful navigation planning, as much of the surrounding land falls within the Blackfeet Reservation where backcountry camping restrictions apply.

The Badger-Two Medicine area holds profound cultural significance to the Blackfeet Nation and remains contested territory regarding resource development. Paddlers should obtain proper permits, respect tribal lands, and prepare for remote conditions with limited rescue access. All watercraft entering Glacier National Park waters require inspection for aquatic invasive species at designated stations along the Two Medicine entrance road or other park locations.