Upper Madison River Fly Fishing in May
The Upper Madison River is the last major, Montana river to be affected by the spring runoff in Southwest Montana each season. The river is rarely “unfishable,” but it can get extremely difficult and even dangerous during the peak flows which will often exceed 4000 cubic feet per second (CFS).
Although Hebgen Dam is the primary source of water that feeds the upper Madison River, various tributaries including Cabin Creek, Otter Creek, the West Fork (of the Madison), Indian Creek, and Ruby Creek surge with water from melting snow during May. The increased flows in these tributaries bring heavy sediment loads and debris into the Madison River during late May and early June, making fly-fishing difficult for a week or two.
The exact timing and duration of the spring runoff are impossible to predict, but we recommend avoiding the Upper Madison the last week of May through the first week of June, based on our two decades of experience guiding this river.
Upper Madison River Fly Fishing Hatches in May
March brown and caddis hatches can bring brown and rainbow trout to the surface in May, particularly on warm, cloudy days.
The Mother’s Day caddis hatch takes place in early May and is one of the more prolific hatch events of the year.
Midges and blue-winged olive mayflies (BWOs) hatch throughout the river on warm, overcast days in early May.
Upper Madison River Fly Fishing Techniques in May
Though dry fly anglers can find fish rising in the right conditions during May, this month fishes best subsurface. Nymphs and streamers are consistently productive until runoff dramatically increases water levels near the middle of the month. After runoff subsides, the entire river starts to fish well and river traffic spreads out as warm weather finally settles across Montana.
Anglers fishing from drift boats enjoy many advantages from throughout the season on the Upper Madison, but boats are particularly helpful in May when rising river levels and reduced water clarity can make wading challenging.
Nymphing from the boats with tandem nymph setups under a strike indicator is a standard and productive Madison River approach.
The streamer fly fishing on the upper Madison gets terrific in the narrow window when the river first starts to go off-color but hasn’t hit peak flush.
Bozeman Fly Fishing Guide Pro-Tip:
As flows rise, larger fish become aggressive in their pursuit to find new holding areas, positioning themselves vulnerable. Fly fishing with large streamer patterns like a Sex Dungeon or Peanut Envy, in darker colors, stripped off the bank can produce some trophy trout. A fantastic stretch for targeting trout in May is drift boating from McAtee Bridge to Varney Bridge.
Our Upper Madison River Fly Box for May
Upper Madison River Fishing Guide Trips in May
Planning a guided trip on the upper Madison River in May should be limited to the first half of the month as runoff can create challenges later in the month.
If your travel plans bring you to the area in late May, our guides can typically find fishable water, but flexibility is the key to success during variable water conditions.
Our Bozeman, Montana base of operations allows us to change our plans if needed when river conditions deteriorate during the spring runoff.
Upper Madison River fishing trips take place throughout the Madison Valley with an emphasis on the stretches between the Palisades Fishing Access Site and the town of Ennis. Guides will go a bit further up the valley to fish the Pine Butte to Palisades section of the river if the West Fork of the Madison unexpectedly becomes dirty.
Anglers of all skill levels can enjoy fly fishing the Madison River in early May. Expert anglers will enjoy the challenges of executing precise casts next to the banks and mid-river boulders with dry flies, dry droppers, or streamers and sink-tip fly lines. Madison River rainbow and brown trout actively feed on various aquatic insects and small fish during this pre-runoff period. Novice anglers will find success and improve their skills fishing with nymphs or lightly weighted streamers under a strike indicator.
Our seasoned Montana fishing guides have over two decades of experience managing excursions through the runoff period with great success.
Upper Madison River guided day trips can be reserved online, through e-mail, or by calling us at 1-406-468-5019. Our experts are here to help, use our Contact Form for help with planning your Montana fly fishing trip.