The Boulder River is a tributary of the

Yellowstone River The Yellowstone River is a tributary of the Missouri River, approximately long, in the Western United States. Considered the principal tributary of upper Missouri, via its own tributaries it drains an area with headwaters across the mountains an ...

, approximately 60 mi (96 km) long, in south central

Montana Montana () is a state in the Mountain West division of the Western United States. It is bordered by Idaho to the west, North Dakota and South Dakota to the east, Wyoming to the south, and the Canadian provinces of Alberta, British Colum ...

in the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territo ...

. It is one of two rivers named the Boulder River in Montana. It rises in the

Gallatin National Forest The Gallatin National Forest (now known as the Custer-Gallatin National Forest) is a United States National Forest located in South-West Montana. Most of the Custer-Gallatin goes along the state's southern border, with some of it a part of North- ...

in the

Absaroka Range The Absaroka Range ( or ) is a sub-range of the Rocky Mountains in the United States. The range stretches about across the Montana–Wyoming border, and at its widest, forming the eastern boundary of Yellowstone National Park along Paradise Va ...

in southern Park County. It flows north through mountainous

canyon A canyon (from ; archaic British English spelling: ''cañon''), or gorge, is a deep cleft between escarpments or cliffs resulting from weathering and the erosive activity of a river over geologic time scales. Rivers have a natural tendency to ...

s, a cataract under a natural bridge, and northwest in a widening valley past McLeod. It joins the Yellowstone at Big Timber. The landscape of the Boulder River and river valley has merited the filming of two movies: ''A River Runs Through It'' and '' The Horse Whisperer''.

Discharges

Tourism

The river is a popular destination for

fly fishing Fly fishing is an angling method that uses a light-weight fishing lure, lure—called an artificial fly—to catch fish. The fly is Casting (fishing), cast using a fly rod, Fishing reel#Fly reel, reel, and specialized Fly line, weighted line. T ...

. Other attractions in the valley include several church camps, a

guest ranch A guest ranch, also known as a dude ranch, is a type of ranch oriented towards visitors or tourism. It is considered a form of agritourism. History Guest ranches arose in response to the romanticization of the American West that began to occur ...

, and several

USFS The United States Forest Service (USFS) is an agency of the U.S. Department of Agriculture that administers the nation's 154 national forests and 20 national grasslands. The Forest Service manages of land. Major divisions of the agency inc ...

campground A campsite, also known as a campground or camping pitch, is a place used for overnight stay in an outdoor area. In British English, a ''campsite'' is an area, usually divided into a number of pitches, where people can camp overnight using ten ...

s. The Forest Service also maintains several guard stations,

trailhead A trailhead is the point at which a trail begins, where the trail is often intended for hiking, biking, horseback riding, or off-road vehicles. Modern trailheads often contain rest rooms, maps, sign posts and distribution centers for information ...

s, and picnic areas in the valley.

Variant names

The Boulder River has also been known as: Rivers a Cross, Rivers across, and Rivers-across. And, to distinguish it from the other Boulder River in Montana, it is sometimes called the "East Boulder River" (as it is east of the other) or the "Boulder Fork of the Yellowstone," parallel with the Clark's Fork of the Yellowstone as differentiated from the Clark's Fork River of Western Montana.

References

{{authority control Rivers of Montana Rivers of Park County, Montana Bodies of water of Sweet Grass County, Montana Tributaries of the Yellowstone River

Discharges

Tourism

Variant names

See also

References