Rainbow trout populations in the Craig section of the Missouri River in Montana average a whopping 5,000 fish per mile. (Shutterstock image)
August 12, 2021
By Andrew McKean
Big water, big fish, big hatches and big crowds. That's a fairly accurate description of Montana's blue-ribbon reach of the Missouri River, generally located between Helena and Great Falls, and almost all of it within sight of Interstate 15. This water is one of the classic tailrace trout fisheries of the West.
The stretch that gets most of the attention from trout anglers is below Holter Dam, a bottom-release structure that discharges cold, clear water no matter the month. That means that when many freestone trout streams in the West are blown out by runoff from melting mountain snowpacks, the Mo is fishing just fine.
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That consistent water has created an unbelievably productive trout fishery. Montana Fish, Wildlife & Parks technicians electro-shock the river annually to assess population trends, and report that rainbow trout populations in the Craig section average a whopping 5,000 fish per mile, while brown trout average about 900 fish per mile. Those are fish over 10 inches long.
Downstream, in the less popular Cascade reach of river, adult rainbows average about 1,600 fish per mile, while browns average about 300 per mile.
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CROWD CONTROL Before we get to how to fish the Missouri, it's useful to note how busy it can be. For the past several years, the "blue ribbon" reach of the Missouri, the 31 miles from Holter Dam downstream to the Hardy Bridge near Cascade, has ranked first in the state in terms of angler days. In 2015, the last year for which Fish, Wildlife & Parks has valid numbers, 183,000 angler days were registered on this stretch of river. According to sources, the last two years have been even busier.
Luckily, the river’s access infrastructure helps distribute those crowds. The river has 15 designated access sites in the blue-ribbon stretch of water—14 managed by FWP and one administered by the BLM.
"If you go on weekends and holidays, you can expect some frustrations," says Chris Strainer, owner of CrossCurrents Fly Shop , with retail stores in both Helena and Craig. "But if you pick your day and your water, you can have a high-quality experience almost anywhere on the river."
Boat fishermen on the Missouri River near Wolf Creek Bridge on Old U.S. Highway 91 in Montana. (Shutterstock image) POTENT PATTERNS Because of consistent water from Holter Dam, hatch progressions are fairly predictable here. Summer season starts with very technical dry-fly fishing. Specifically, fish are looking up for pale morning dun (PMD) mayflies, but because the water is clear, and because fish have so much natural food, they can afford to be picky.
For that reason, "your ability to cast and get good drifts has a more direct impact on the fishing than your flies," says Strainer. Long leaders—10 feet or longer—and pin-point casts are money here. Go-to flies include the Hi-Vis PMD Spinner and the Zelon Cripple, but most guides note that nymphing with small mayfly emergers like Lightning Bugs and Frenchies can be wonderful even when fish are popping on surface bugs.
In June, fishing PMDs in the morning and caddis dries in the evening will attract strikes. And don't give up on the evening bite when the sun quits. The red-hot caddis hatch extends so late into June evenings that you can get action on Elk Hair Caddis and the local favorite Corn Fed Caddis until it’s too late to see rise forms. Some guides report summer solstice fishing can be good nearly until midnight.
A few grasshoppers may turn fish in later July, but that's mainly an August bite, and it’s better downstream of Craig. Instead of relegating yourself to dries, try swinging big articulated streamers for the Missouri’s largest rainbow and brown trout, which can easily go to 20 inches with some trophy specimens taping 24 inches. For browns, nighttime fishing with streamers can be gold.
But any discussion of summer fishing on the Missouri has to include a warning about moss and aquatic weeds. The slower water—back channels, slow-water estuaries and some inside bends—grow prodigious weed beds. Trout use those stands for refuge, but any time the moss drifts in the current, it frustrates flyrodders focused on a drag-free drift. If you don’t get hit after a few artful drifts, check your fly; chances are good it’s fouled with weeds.
Access points on the Missouri River in Montana. KEY ACCESS SPOTS The Missouri River is generous to floating anglers and waders alike. Access points benefit both populations of trout fishers, but let's look at the spots that cater to drift-boaters first.
Many outfitters work the Wolf Creek-to-Craig section and launch either at the Bull Pasture Fishing Access Site (FAS) or downstream at Wolf Creek Bridge. But the most popular reach for boaters is Craig Bridge to either Stickney Creek or Spite Hill, both of which give anglers most of a day to work prime water.
For wade-fishers, several walk-in access sites are prime. They include Bull Pasture, Lone Tree, Dearborn, Mid-Canon and Devils Kitchen. Montana law allows anglers full access of rivers below the high-water mark, which means much of the shoreline is accessible. Just make sure to be respectful of the many private residences along the river.
GO WITH A PRO Learn the lay of the water with a reputable guide.
A good strategy for fishing the Missouri for the first time is to hire a guide for at least a day in order to learn how to fish the river and get an understanding of the best patterns. There is no shortage of fly shops and shuttle services that will connect you with a registered guide who can put you on fish. Some of the most popular commercial outfits on the river include:
SIDE TRIPS Nearby waters can provide a respite from the crowds.
If you’d rather fish smaller waters for smaller trout among smaller crowds, two excellent destinations are within the Missouri River's orbit. The closest is Little Prickly Pear Creek, an important spawning tributary of the Missouri that closely follows Interstate 15 from north of Helena to Wolf Creek. Take Exit 219 off the interstate and follow S. Recreation Road either upstream or downstream to find pocket water inside the Wolf Creek Canyon.
Smaller caddis and attractor dries will take a mix of smallish rainbow, brown and even cutthroat trout in oxygenated pools. Some of the best fishing will be in tail-out riffles below deeper pools, but don't neglect holding water behind boulders and in cut-bank holes.
For slightly larger water, and surprisingly large brown trout, take a road trip over McDonald Pass from Helena. U.S. Highway 12 follows the Little Blackfoot River all the way downstream to its confluence with the Clark Fork River near Interstate 90. The best combination of access, dry-fly fishing and sizeable trout is between Avon and Elliston. The hopper fishing here is wonderful from late July through August (in June you can catch big fish with attractor dries such as Stimulators, Chernobyl Ants and big X-Caddis patterns). This is all wade fishing; the river is too small and shallow for any sort of boat, including shallow-drafting inflatables.
And for a mix of smaller fish but abundant access, turn south off Highway 12 on Little Blackfoot River Road and follow it to the Helena National Forest boundary. From there, you can fish little pools and beaver dams for hand-sized trout all the way upstream to the river’s headwaters.
