Boulder River

The Boulder River originates on Mount Douglas in the Absaroka-Beartooth Wilderness and flows approximately 60 miles north where it enters the Yellowstone River near Big Timber, Montana. The upper reaches of the stream flow through a glacial valley. This stream reach has moderate to steep gradients with flat rocky riffles flowing between widely spaced runs and pools. The stream bed in this reach is made up of primarily boulders and cobbles. The Boulder River from Falls Creek Campground to the Natural Bridge is less steep; gravels make up the majority of the bed material in this reach. The stream in this area has a good mixture of riffles, runs and deep pools. The Boulder River leaves the Gallatin National Forest at the Natural Bridge overlook. The majority of land ownership below the forest boundary is private and access to the stream is limited, although several state fishing access sites are present in this reach.

The Boulder River provides excellent opportunities for wild trout fishing in a beautiful setting. Opportunities for boat fishing are limited to the lower river because the upper portions are too rocky and treacherous. Wade fishing is the most popular form of fishing on the Boulder River. Boulders make wading difficult in many areas in the upper sections of the river so care should be taken when fishing these areas. Native cutthroat trout are restricted to the headwater portions of the stream while rainbow trout and brown trout are abundant in the lower portions of the River.

The Boulder River can be accessed via highway 298 and Forest Road 6639. Many areas are accessible for fishing from the road or campgrounds found within the drainage. In addition several trailheads provide access to small fishable tributaries.