Chi Wulff Header

Missouri River Facts

Back to Rivers


The Missouri River is formed near the town of Three Forks by the confluence of the Jefferson, Madison and Gallatin Rivers.  The “Mighty Mo” is the longest river in America.  It spends 783 miles in Montana before crossing into North Dakota.  The Missouri River flows north from Three Forks to Great Falls, where it bends east toward North Dakota.  The Missouri River is one of the most famous rivers in Montana, perhaps the entire United States


The Missouri has the most diverse list of fish species in Montana.  In the river there are rainbows, browns, cutthroats, lake trout, Chinook salmon, black and white crappie, large and smallmouth bass, channel catfish, burbot, lake and mountain whitefish, carp, northern pike, walleye, sturgeon, paddlefish, yellow perch, gar and more.  On some sections of the Missouri River, you hardly know what you are going to catch next. 

The most popular and perhaps the best water is a 48 mile stretch from Holter Dam to Cascade.  The Missouri River can be broken up into three sections.  The first of these is the headwaters to Holter Dam.  This area produces good numbers of average size trout, but the fishing is not as good as it is downstream.  Holter Lake produces great numbers of large rainbows in the spring. 

The second section is from Holter Dam to Cascade.  This tailwater fishery provides the best trout fishing on the Missouri all year round.  This is the area that most fly fishermen visit.  Fishing is consistently and surprisingly good here all year round.  This is also the most crowded stretch of water in Montana, with far more that 100,000 fishing days a year.  The fish in this section of the Missouri average 12-14 inches, but larger trout are very common. 

The final section of river is from Cascade to the North Dakota Border.  This section sees the river slow down and warm up.  Fort Peck Lake, the largest reservoir in Montana is in this area of the Missouri.  The trout fishing is still good, but warmwater species are more common. 

Seasonal Strategies:

The tailwater below Holter Dam fishes well all year.  In the winter, look for scattered midge hatches.  Beadhead nymphs and streamers fished deep and slow will catch fish.  A two nymph rig beneath a strike indicator is a good bet.  Spring sees rainbows spawning in the tributaries.  Your chances of catching large browns on streamers are best in the spring.  Nymphing is the best way to consistently catch fish during the spring. 

Mid-April through June features one the Missouri’s best hatches, Baetis.  Look for this hatch on the afternoons on cloudy, rainy days to see the best action.  During the spring, the larger fish hang out in the skinny water- six to 24 inches deep.  Spring fishing is best conducted from 10 am to 4 pm.  In June caddis and PMDs begin to hatch in earnest.  In mid-July, Tricos show up, lasting until mid-September.  Think small flies (#22 is about right) and little leaders. 

In early August, terrestrial patterns like hoppers, beetles and ants will produce good fish.  Terrestrial fishing lasts until mid-fall.  The October Caddis hatch can be very impressive if you can find it.  Fall is also a wonderful time for streamers in deep holes and pools. 

Special Regulations:

The Missouri River is open all year.  The entire river is catch and release for cutthroats.  There are many regional regulations in effect, check with a local fly shop before fishing.

Access and River Mileage:

The Missouri River flows 783 miles in Montana.  Access is good on almost all of it except for the tailwater below Fort Peck Reservoir.  Below Holter Dam can become incredibly crowded during the season.  To beat the crowds, either fish early or fish in the off season.  There are boat launches every few miles along the Missouri River.  Finding wade fishing access is also very easy. 

Special Cautions:

Watch out for whirlpools and strong currents when floating the Missouri

Waders should be wary of strong currents. 

Rattlesnakes thrive along the banks of the Missouri, so avoid sections of deep brush and tall grass.