Fly fishing the Gallatin River while floating is permitted between Manhattan and Three Forks, Montana. This scenic waterway has limited public access with sparse trout populations, yet offers a nice change of pace for anglers fishing near Bozeman during the summer season.
Gallatin River fishing is open to float angling downstream of its confluence with the East Gallatin River, near Manhattan, MT. Public access is limited to Nixon and Logan bridges along the “lower Gallatin,” making float angling preferred over wading. The six-mile stretch between these two bridges is a diverse waterway with good numbers of Rainbow and Brown Trout and an occasional Westslope Cutthroat.
The river flows along the base of the Horseshoe Hills, lining the river with dramatic bluffs and arid hillsides. The river’s character features riffles, pools, and long runs intermixed with side channels and small islands.
Cottonwood groves are dense in places and high water during the spring will often create new channels, bring downed trees into the river’s main channel. Caution is advised to anglers floating the lower Gallatin during the first few weeks following peak runoff flows.
Trout populations are somewhat transient in these lower stretches of the river. Little is truly understood about the trout movements here, but it is thought that the summer months hold the most trout as fish from the Missouri River move up the Gallatin in search of cooler water. Rainbow and Brown Trout migrate further upstream during their prospective spawning seasons. High water displaces many of the resident fish, which work their way back into the system, dispersing upstream as flows stabilize in late June or early July.
The river is relatively small and trout populations are sparse, so heavy angling pressure can impact the quality of the angling experience. Many anglers rightfully avoid fishing here when they see other anglers or their vehicles already present at boat launches and access sites.
Anglers floating the lower Gallatin River can quickly cover the distance between the Nixon and Logan bridges in 2-3 hours, focusing their efforts on streamer fly fishing the best water.
Floating and wading can provide a full day’s worth of fly fishing near Bozeman on the lower Gallatin. Fish the deepest water from the boat while stopping to work myriad side channels and island runs with dry/dropper or nymph rigs.
Upstream irrigation dewaters the mainstem of the river as it snakes its way through the Gallatin Valley in the summertime. Anglers fly fishing the Gallatin during the summer are advised to check current regulations as “Hoot Owl” restrictions are common in June and July on the lower river.
Floating the lower Gallatin is optimal when streamflow is between 800 and 500 CFS, caution is advised during higher flows and can be very challenging below 300 CFS
The Nixon boat ramp has a small parking area that isn’t designed for significant parking of vehicles with trailers and is best for 3-4 at most. The ramp was restructured after high water in 2022, making for an easier launch. The Logan Bridge offers shoulder parking for vehicles but the boat ramp is a steep cut into loose sediment on the riverbank requiring 4WD or AWD vehicles.
Downstream of Logan Bridge, the river undergoes a transformation, characterized by long riprap banks and deep holes that serve as the primary holding areas for trout populations. The long, shallow runs between deep holes rarely hold significant trout numbers.
The river bottom is lined with cottonwoods as it flows through agricultural hayfields and pastureland. Private lands surround the river, eventually giving way to public lands associated with the Missouri River Headwaters State Park. The lowest sections of the river can change dramatically from one year to another as high flows cut through unstable islands, creating new channels filled with debris that can challenge both anglers and floaters alike.
The best fly fishing on the Gallatin, downstream of Logan is found in the first 3 miles below the bridge. Anglers fishing here do well with tandem nymph setups, fished through the deep runs and pools created rip rap reinforced banks along the railway. Hatches are sparse and dry fly fishing is rarely as productive as subsurface techniques.
The river cuts through unstable river bottom during its final journey to its confluence with the Jefferson and Madison to form the Missouri River. Deep holes along undercut banks are filled with sunken debris that trout reside in throughout the summer months. Streamer fly fishing or precision nymph fishing is required in these scenarios.
The last mile of the float features a few stable pools and runs that hold a few resident trout throughout the year. Ample public access and the mixed nature of recreational use of the river here limits its productivity for even the most skilled angler.
The last few hundred yards of the float are on the Missouri River, with the takeout on river right at a well-marked boat ramp in the Missouri River Headwaters State Park.
The Logan Bridge offers shoulder parking for vehicles, but the boat ramp is a steep cut into loose sediment on the riverbank requiring 4WD or AWD vehicles. The Missouri Headwaters ramp is a well-maintained concrete ramp with ample parking. Note that vehicles without state license plates are required to pay a day-use fee to use the facilities with the state park.
