Our Rivers

Yellowstone River Fishing in May

Yellowstone River Fly Fishing in May

Through May, mountain snowpack swells the Yellowstone as runoff creeps closer, muddying the river and filling its vast network of channels. The weeks leading up to runoff can offer exceptional fishing as trout respond to warming water and prolific insect activity, culminating in the Mother’s Day caddis hatch.

Expect runoff to hit the river sometime in early to mid-May, rendering the main-stem waters un-fishable for 4-8 weeks. During this time, it is best to avoid the river as conditions are not safe for floating or wading anglers.

Yellowstone River Fly Fishing Hacthes in May

The Mother’s Day caddis hatch is temperature dependent, so the dates vary from year to year. We generally expect the hatch to start between late April and early May.

Many Montana anglers watch the Fins and Feathers Yellowstone River fishing report closely this time of the year to track the hatch progress.

March brown and blue-winged olive (BWO) activity is heavy on overcast days in early May, and they will hatch concurrently with the Caddis.

Yellowstone River Fly Fishing Techniques in May

Anglers across Montana hope for optimal conditions and exceptional dry fly fishing during the Mother’s Day caddis hatch on the Yellowstone. Popular fly patterns for the hatch include size #12-#16 Elk Hair Caddis in peacock or dun.

Anglers of all skill levels will find success with dries when the river is in good condition and the hatch activity is heavy.

Dry/dropper rigs with attractor patterns such as a Royal Wulff or Chubby Chernobyl in sizes #10-#12 with a lightly weighted caddis pupa pattern can be highly effective throughout the hatch. When trout are rising sporadically, our guides will fish an unweighted soft hackle to imitate a swimming caddis pupa just below the water’s surface.

If you’re not seeing many insects and fish aren’t rising, fish are still probably feeding subsurface. Try fishing tandem nymph rigs under a strike indicator, streamer fishing, or slowly swinging a soft-hackle. Just about every trout in the river will be feeding as the Mother’s Day caddis hatch looms.

Bozeman Fly Fishing Guide Pro-Tip:

Fish big, dark nymphs and streamers to contrast the changing water conditions, targeting areas with slower water along the bank or behind large structures that break the current. Stay safe when fishing this time of year, especially when the river is high and off-color.

Our Yellowstone River Fly Box for May

Yellowstone River Fly Fishing Trips in May

Yellowstone River fishing trips in May are limited by the conditions on hand, which are impossible to predict more than a few days in advance. Some years, the river is completely unfishable by late April, while others see our guides on it daily through the middle of the month.

We have plenty of Montana fly fishing options near Bozeman as backups to Yellowstone River fishing in early May. When the Yellowstone blows out, we shift our local focus to the Upper and Lower Madison Rivers, as they remain fishable longer than the Yellowstone at the start of the runoff.

The Bozeman fly fishing guides at Fins and Feathers also operate on the Missouri River near Craig, Montana from April through June. Missouri River fishing trips are great experiences in themselves when most Montana rivers are brown with runoff.

Anglers of all skill levels can expect to learn a variety of fly-fishing skills on a guided trip with our experts in early May. Conditions on the Yellowstone River can change quickly this time of year, however, and anglers should remain flexible to ensure success.

Bozeman has world-class fly fishing in every direction, so you can count on our 23+ years of experience to find suitable alternatives when river conditions change.

Contact Us to learn more about planning a Yellowstone River fishing trip with our Bozeman fly fishing guides. Reservations can be placed online, via e-mail, or by calling us at 1-406-468-5019.