Description: The Sun River starts in a deep canyon, runs through prairie grasslands and finally meanders past cottonwood bottoms on its way to the Missouri. In the upper river, horizontal upthrusts create ledges of rock that cross the river and create challenging rapids.
Vital statistics: 101 miles long from Gibson Dam to the Missouri River at Great Falls.
Level of difficulty: Class I and II at normal flows with occasional harder spots. Very difficult water (Class 5) for 2.5 miles immediately below Gibson Dam. Excellent canoeing stream for solid intermediate paddlers.
Flow: Annual mean flow: 696 cfs near Vaughn. Gibson Dam has erratic flows. Flows may be low during spring runoff and high in the fall. Minimum floating level is 400 cfs. Anything over 3,000 cfs is for experts only.
Hazards: Rock gardens, ledges, standing waves, diversion dams, snags. Big winds.
Where the crowd goes: Access below diversion dam to U.S. Highway 287 bridge.
Avoiding the scene: Between US 287 and Vaughn, where you'll find only an occasional fisherman or ranch hand cooling off.
Inside tip: When many streams are high and muddy with spring runoff, the Sun may be perfect.
USFS: Lewis and Clark (Rocky Mountain Division), Bob Marshall Complex
USGS: Choteau-MT, Great Falls-MT
Maps:: BLM: #29 (Choteau), #39 (Great Falls North)
River rules: Mostly private land, camp within high-water marks. If you camp or hike on state land, a recreational-use permit is required.
For more information: FWP, Great Falls; Medicine River Canoe Club, Great Falls.
The paddling: The Sun River cuts a handsome swath through a narrow canyon, unlike any other in Montana, as it wends its way out of the remote Bob Marshall Wilderness. Many historians have remarked on the beauty of this stream as it plunges out of the mountains. Its towering sandstone formations, multi-colored rocks, occasional waterfalls, and parched surroundings make it look like a river of the southwestern United States. The canyon between the diversion dam access and U.S. Highway 287 is a geologist's delight of thrusts, folds, uplifts, and layers of sedimentary rock. They tell a story of how this land was formed. The area surrounding the river has special significance to the Blackfeet Indians, who defended it fiercely.
The Blackfeet knew the Sun as the Medicine River, reportedly because of unusual mineral deposits along its banks which possessed remarkable medicinal properties. One can only speculate on how the river came to be known as the Sun. The river flows directly east, causing it to reflect the sun in the morning and evening hours. Viewed from afar, it often appears as a ribbon of light.
What must once have been a bronco of a river has since been tamed and bridled. Gibson Dam, built in 1913, blocks the river's flow. Then 2 miles below Gibson there's a large diversion dam. Approximately 97 miles of the Sun remain free-flowing, but they, too, have felt the hand of man.
The river remains strikingly beautiful as it leaves the sheer walls of the majestic Rocky Mountain Front. Sawtooth Ridge rises prominently from the south side of the river, and Castle Reef juts just as spectacularly to the north. If the river weren't so tricky, there would be a real temptation to float down the river backward.
Along parts of the upper river the stream bottom is solid bedrock and smooth as a pool table. In other places, reefs of rock cross the river, creating ledges and sharp drops. Experienced hands can maneuver around most of the these ledges, but some drop several feet and require caution, especially for canoeists. Rocky riffles alternate with large, extremely deep pools that are excellent swimming holes in the heat of summer. Surrounding cliffs make good jumping platforms. The water is deep, emerald-green, and usually quite clear.
The canyon section of the Sun starts immediately below the diversion dam (a short distance above an old bridge) and continues for about 25 river miles to the bridge over US 287. When water flows are low, it's a long two-day trip, as the river meanders a great deal. The constant maneuvering will wear you down. When the water is high, it's a riproaring whitewater trip that can be done in six to eight hours. Be aware of two diversions, one at mile 81 and Floweree Diversion at mile 74. The first can be run with caution, but Floweree may have to be portaged on river right.
The narrow canyon of the upper river eventually gives way to open, agricultural land after the US 287 bridge. Rolling, grass-covered hillsides dominate the landscape, and deer, antelope, and coyotes can often be seen from the river. While the river generally gets easier, several difficult rapids can be found about 4 or 5 miles below the US 287 bridge.
About halfway between the US 287 bridge and Simms, cottonwood groves become denser and willows thicken, creating excellent fish and wildlife habitat that lasts all the way to Vaughn. Fishing for brown trout can be good when the river isn't seriously dewatered. The river bottom between the US 287 bridge and Vaughn is isolated and largely undeveloped, even though civilization isn't far away. Most of the land along the river is privately owned and access comes via county bridges. Be careful of the Fort Shaw Diversion, 3.5 miles above Lowry Bridge. Portage on river left.
Below the town of Sun River the water slows and becomes heavily silted at Vaughn with the entry of Muddy Creek. It's not really very scenic after this, as the river more closely resembles a big ditch. A major diversion, Rocky Reef, 2.5 miles above Fort Shaw, needs to be portaged on river right.
The entire Sun River receives only moderate floating pressure. Access is limited and the scarcity of public land limits the amount of overnight camping (although stream access law permits camping within the high-water marks of major rivers provided you aren't within sight of, or within 500 yards of, an occupied dwelling).
The Sun's difficulty is directly proportional to its flows, which can be irregular. Although the Sun is a sizeable river, it has frequent agricultural diversions and the releases from Gibson Dam are unpredictable. In some years, even spring flows may be too low for floating. In other years, the river may be bank-full and very challenging. Check flows before you go by calling the numbers or checking the websites listed in Appendix A. Minimum floating level is 400 cfs. Or if you prefer, use low-tech and take a look at the river gauge on the northwest side of the US 287 bridge near the old bridge abutments. If the gauge reads below 2 feet, forget it. At 2 feet, it's marginal, but possible if you read water well.
While intermediate canoeists and rafters will find the rock gardens and ledges of the upper Sun great fun, these hazards will eat up beginners. Much of the upper river calls for quick maneuvering and excellent boat control. Some of the runs should be scouted. When the river is very high, large standing waves can spell trouble for open canoes. Below the US 287 bridge, the rapids and ledges gradually give way to occasional cottonwood snags and numerous diversion dams. It's easier, but still too much for beginners. Anyone can handle the river below the town of Sun River.
Much of the land surrounding the Sun is used intensively for irrigation. The frequent diversion dams take large gulps of water out of the river, sometimes leaving it almost completely dry. Erratic flows not only limit recreation, but they hurt wildlife as well. Fluctuating flows from the dam may keep a healthy riparian zone from establishing and may hurt aquatic insect populations, to the detriment of species further up the food chain like beaver, mink, waterfowl, and trout. This river sorely needs consistent flows as well as regulations that retain a minimum amount of water instream.