Boulder River Fly Fishing Guide

							Boulder river fishing angler hook up

Boulder River MT

The Boulder River is a beautiful watercourse that flows into the Yellowstone River near Big Timber and originates in the Absaroka-Beartooth Wilderness.

If you plan to flyfish Montana on the Boulder River, make sure you take a quick detour to the Natural Bridge Falls. These falls separate the upper and lower river sections and are a sight to behold.

The best fly fishing in Montana on the Boulder River is downstream of the Natural Bridge Falls, after the East and West Boulder rivers join the mainstem. Although the last 35 miles of the river offer limited public access and difficult wading conditions, they also naturally restrict angling pressure, making it an ideal spot for Montana fly fishing enthusiasts.

Best Guided Fishing Trip Ever

"The most incredible fishing experience of our lives. My son had never caught a fish on a fly rod and I hadn’t caught many. We wanted to learn so we booked a full day fly fishing trip with Fins & Feathers. By the end of the day we both had caught dozens and missed 10 times as many (still learning!) So exciting to watch the fish snatch the flies off the surface! At the end of the day my son proclaimed it was the best fishing trip he’s ever been on, and I have to agree."

- Bruce M.


Boulder River Fly Fishing Sections


							Boulder River falls at the Natural Bridge

Above Natural Bridge Falls

The upper 22 miles flow through a narrow, forested canyon with a mix of private and public lands. This scenic stretch of river offers trout fishing for native Cutthroat and wild Rainbow Trout.

A forest service road follows the river, providing convenient access along the upper stretches. Expect busy summer traffic as this is a popular area for recreation and is home to numerous summer camps and church retreats.

The crystal-clear waters flow through riffles, rapids, pools, and runs in this upper section. The river slows and widens just before the rapids above the Natural Bridge Falls.

							Flyfishing Montana on the Boulder River is best from rafts.

Lower Boulder River

The East and West Boulder rivers join the mainstem downstream of the Natural Bridge Falls. Here the river begins to widen as it flows through an expanding valley and is lined with Cottonwood Trees and agricultural fields.

Fishing access can be found at the Boulder Forks and Big Rock FAS areas. The river is aptly named and full of boulders in every shape, size, and color. The Boulder River is home to some of the pocket water fly fishing in Montana.

Floating the Boulder River is an incredible Montana fly fishing trip, however, timing is crucial as optimal flows are between 800 – 1400 CFS.

Fishing Conditions Through the Seasons

April Fishing

The long winter starts to abate in early April on the Boulder River as overcast skies bring BWO and March Brown mayfly hatches near Big Timber...

Read More

May Fishing

Runoff from melting snow and May showers bring runoff conditions to the Boulder River by mid-May. Expect dry fly fishing to persist through early...

Read More

June Fishing

High-water conditions make for difficult Montana fly fishing conditions on the Boulder River through the latter part of June when the river crests...

Read More

July Fishing

The best fly fishing in Montana on the Boulder River is during the first two weeks of July when the water temperature and streamflow are ideal for...

Read More

August Fishing

Boulder River fly fishing in August is best suited for wading anglers who are willing and able to cover a lot of ground during the early morning hours...

Read More

September Fishing

The arrival of fall brings cooling water conditions and the reappearance of blue-winged olive hatches and rising trout throughout the lower Boulder River...

Read More
							Wading angler fly fishing in Montana on the lower Boulder River

Boulder River Fly Fishing Trips

Late June and early July is the primetime for Boulder River fly fishing trips with the Bozeman fly fishing guides of Fins and Feathers. The exact timing varies yearly, but we target the Boulder River when the streamflow is between 900 - 1500 CFS.

This is a scenic Montana river with good numbers of Rainbow and Brown Trout in the 10-14" range that are typically eager to take a well-presented dry fly.

Boulder River fishing trips are best suited for anglers with intermediate to advanced fly fishing skills. Guests should have good mobility to assist with boat launches and occasional portages around river obstructions.

Montana Fish of the Boulder River

Ask Us A Question