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When to fly fish Montana’s Missouri River? Whenever you dang well can.

A fly-by-fly breakdown of the very best months to get yourself to Montana's fly fishing paradise

The mighty Missouri River in Montana offers mighty fine fishing year-round, but the best months are April through October. It just depends on how you like to fish, what you like to fish with, and your heartiness factor.  

This month-by-month, bug-by-bug breakdown of fly fishing on the finest river in the west will give you a sense of what to expect during the height of the fishing season: 

April: If there’s an official season kickoff, it’s April, but it ain't for the faint of heart. While the weather can be inclement, the nymphing and streamer fishing can be stellar. Dry fly stuff this early in the season is hit or miss, despite midges and blue winged olive (BWO) hatches. Fish have minds (albeit tiny) of their own and they decide when they like to rise; in April those days are few and far between. Nevertheless, April delivers exceptional fishing and relative solitude on the river. Also, we offer a spring special to get you motivated. Bring warm clothes.

May: As the days warm up in May so do the water temps. Dare, I say, May may be the best streamer and nymph fishing month. BWOs and some march brown mayflies are featured on the menu and the Mother's Day caddis also make an appearance. With the proper weather conditions, surprisingly good dry fishing can occur, but like April, it’s random. If you like to avoid the crowds, May is your month. 

June: Next up is the magical month of June. Air and water temps begin to climb to create optimal hatches of the season. Around mid-month the water temperature reaches perfection for our glorious pale morning dunn (PMD) hatch, which is a daily drill for a month or so, along with a major caddis hatch. Dry fly nirvana! The only two drawbacks to June fly fishing are the potential for big water and big crowds. Depending on winter snowfall and run-off, potentially high water mid-month can make dry fly fishing challenging at best and just plain impossible at worst. However, on the flip side, high water makes for insane nymph fishing. Also, June is bustling with anglers on the Mo'. You must book a year out to even have a chance of securing good guides and lodging. You snooze, you lose. But if you plan ahead, June might just give you the ultimate fly fishing experience.

July: While May is the best for streamers and

nymphing, July is arguably the best for dry fly

fishing. Mayflies, caddis and tricos are the things to throw; we like to throw hoppers as well. The trico hatch happens about mid-month and turns into an unbelievable scene! Thick clouds of bugs swirling up into the sky. This crazy sight alone is worth the trip. No high water in July; just consistently spectacular dry-fly fishing, which delivers consistently big trout on the end of your line. Nymph fishing is good but more technical. Planning ahead still applies in July. You won’t find solitude, but you will find a whole lotta bugs and a whole lotta fish. 

August: August is the real sleeper. Hot daytime air temperatures drive river temps to their highest of the season. Fishing remains good, but we like to start early and be done early. Hopper fishing is the deal in August bolstered by mega trico hatches still happening daily. Many guides take a week or two off this time of year. I like to keep going in August because the crowds are gone and the potential to catch a giant on hoppers is real! Nymph fishing continues to be great, but it’s different due to aquatic vegetation. 

September: September brings with it some cooler weather, which brings some better hatches. Caddis come back, along with a hatch of small mayflies called pseudos. Later in the month, the blue winged olive returns, driving rainbow trout crazy. Big pods of dry-fly eaters. What a spectacle! In September, we also start throwing some streamers again, and nymph fishing is off the chain! The crowds return a bit, so make plans early.

October: October eclipses September with even bigger BWO hatches and bigger pods of rainbows. The brown trout become more unpredictable, but they still like to chow on little nymphs and some big meat. Fewer humans hanging around now, which is a plus, so it’s easier to get guides and lodging. But the weather can be rough at times. Bring your waders and warm clothes.

So, the resounding answer to the question about when to fly fish the Missouri River in Montana remains the same: whenever you damn well can. But April through October offer exceptional fishing opportunities – each month presenting its own unique conditions and challenges. Whether you prefer battling the elements for solitude or enjoying the hatch swarms alongside other anglers, this special place offers it all. We still have dates available for summer 2024. Give us a call and let’s plan your first or next fly fishing adventure. 


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