May is the peak month for spring fly fishing in Montana. By the first of the month winter is in the rearview mirror, mayflies are hatching in full force, and anglers can expect some of the best fly fishing of the year on our blue ribbon rivers. The Missouri River is the main event in May for our anglers and Montana fly fishing guides. Strong hatches of Blue Winged Olives (BWOs), the Mothers Day Caddis Hatch, and March Browns make for some of the best dry fly fishing of the year on the Missouri River.
Anglers fishing with us at our Missouri River Basecamp can expect great catch rates on a daily basis with excellent nymphing each morning followed by great sight fishing with dry flies all afternoon. The Mothers Day Caddis Hatch also cycles through our freestone rivers closer to Bozeman, MT before they enter run-off in the middle of the month and is generally the densest hatch our rivers see on an annual basis.
- Some of the highest catch rates of the year on the Missouri River
- Consistent hatches throughout the month of May on the Missouri River make for quality dry fly fishing most afternoons
- The Mothers Day Caddis hatch also cycles through our freestone rivers including the Yellowstone River, Madison River, and Gallatin River, generally making for phenomenal pre-runoff dry fly fishing
- Anglers can count on generally reliable weather making for consistent fly fishing conditions across Montana in May
What to Expect
May is one of our favorite months for fly fishing in Montana. Our fly fishing season is in full swing and our anglers and guides are out daily enjoying great fly fishing across the state. The first half of May is generally pre-runoff conditions on our rivers close to Bozeman, MT and daily hatches of BWOs early in the month make for great fly fishing on the Yellowstone and Madison Rivers.
By the 15th of the month, warmer temperatures result in significant snowmelt at upper elevations, marking the beginning of run-off on our freestone rivers. Generally the Yellowstone River, Madison River, and Gallatin River experience elevated flows not suitable for fly fishing from May 15th-June 25th. The exact dates vary year by year, but we strongly recommend all anglers planning Montana fly fishing trips during this time frame consider the fly fishing on the Missouri River instead.
Anglers can expect quality fly fishing on the Missouri River on a daily basis on the Missouri River throughout the month of May in Montana. The Missouri River tailwater below Holter Dam doesn’t experience the crippling effects of runoff our freestone rivers see on an annual basis. Instead the Missouri River runs high but clear making for some of the best fly fishing of the entire season in Montana. The nymph bite can be silly good. Consistent hatches of mayflies and caddisflies make for excellent sight fishing. On higher than average years when flows exceed 9000+ CFS, the dry fly fishing becomes difficult, but the nymphing for trophy trout becomes even better.
Where to Fly Fish in May
At this point it should be no surprise that the Missouri River is our first choice for May fly fishing in Montana. Strong hatches, limited runoff, and some of the highest catch rates of the year make for a winning combination for a Montana fly fishing trip. While the Missouri River is not a secret amongst Montana anglers and you shouldn’t expect solitude on the river, there is plenty of open space for everyone to enjoy the world-class fly fishing. Many of our long time anglers come back year after year to fly fish the Missouri River in May, making it truly a favorite Montana fly fishing trip.
Our rivers closer to Bozeman, MT including the Madison River, the Yellowstone River, and Gallatin River are also suitable for an early May Montana fly fishing trip. From May 1st to May 15th anglers can count on favorable conditions and strong hatches of BWOs and the annual Mothers Day Caddis Hatch. Our annual runoff begins by the 15th of the month, leaving these rivers largely unfishable. The Paradise Valley Spring Creeks and area lakes are the best alternatives for anglers in Bozeman, MT. Or the short road trip to our Missouri River Basecamp in Craig, MT for some of the best fly fishing of the year.
May Fly Fishing Tactics
Anglers can count on consistently good nymphing on all our area rivers throughout the day in May and quality dry fly fishing in the afternoons. Pressure is still relatively low through the month of May so anglers can generally get away with fishing larger attractor patterns and expect to do well. Strong hatches of mayflies and caddisflies keep our fish on the feed.
On the Missouri River anglers can expect some of the best nymphing of the year. Getting down and dirty in the mornings is generally the most productive tactic and sowbugs are king on the Missouri River tailwater. Our Montana fly fishing guides generally fish a tandem nymph rig consisting of two sowbugs or a large attractor like a worm or scud #6-12 followed by a sowbug on a daily basis. By the middle of the month mayflies and caddisflies become equally important and pheasant tails (#12-20) and caddis pupa (#14-18) are great second fly options.
The dry fly fishing on normal and low water years can be excellent in May. Expect great hatches of BWOs early in the month, followed by the Mothers Day Caddis hatch in the middle of the month, and March Browns out in full force through the end of the month. The dry fly fishing on the Missouri River is always technical. Expect cripples, emerges, spinners, and spent patterns to out fish their larger counterparts.
Anglers fly fishing the freestone rivers in May can expect to do well nymphing with larger stonefly nymphs and worms (#6-10) followed by attractor nymphs (#14-18). Streamer fishing can also be effective on these rivers in May, with large articulated streamers bringing large trout to net once flows start to rise. Dry fly fishing is less technical on the Yellowstone and Madison Rivers, anglers armed with small parachute adams and hi-viz caddis patterns (#16-18) should expect to do well in the afternoons.
May Fly Fishing Trips
May fly fishing trips with the Montana Angling Company largely revolve around the great fly fishing on the Missouri River from our Missouri River Basecamp in Craig, MT. Early in the month anglers should consider the rivers in Bozeman, MT to also be good options, but by the middle of the month there is nowhere better to fish than the Missouri River.
Missouri River fly fishing trips in May are well suited for anglers of all skill levels. Seasoned anglers will enjoy the great sight fishing with dry flies and nymphing for trophy trout. Beginner anglers will have consistent success and great learning opportunities. Our guides generally book well in advanced for Missouri River fly fishing trips in May as does lodging. We encourage anglers interested in our May fly fishing trips at our Missouri River Basecamp to contact us to learn more.