Montana Fly Fishing 5 min read

DIY Guide to Fly Fishing the Dearborn River in Montana

Ken Sperry

Posted by Ken Sperry

February 24, 2024

Dearborn River in Montana

Fly fishing on the Dearborn River offers a unique opportunity for anglers of all levels to enjoy the pristine wilderness of south central Montana. The river boasts a diverse ecosystem providing an ideal habitat for various trout species, including rainbows, browns, and the native cutthroats. It flows from the rugged terrain of the Lewis and Clark National Forest and continues its journey through canyons and valleys, presenting a picturesque backdrop for the perfect cast.

Anglers seeking to venture into DIY fly fishing on the Dearborn require specific knowledge to make the most of their experience. Understanding the river’s seasonal patterns is crucial, as is choosing the right equipment and flies. Moreover, the river can present challenges with its varying flows and temperatures, demanding flexibility and adaptability from the fly fisherman.

Below, you will find information to help plan your trip to Dearborn River including information on access points. The guide can help you put together the perfect trip.

Understanding the Dearborn River

Fly fishing the Dearborn River in Montana

The Dearborn River originates in the Lewis and Clark National Forest close to Scapegoat Mountain. The tributary stretches for 70 miles before it ultimately ends in the Missouri River near the town of Craig, MT. Some liken the river to a smaller version of the Smith River.

A lesser-known fly fishing haven, the Dearborn offers unique opportunities within its waters and surroundings. Its geographical diversity and seasonal variances play a pivotal role in fishing experiences.

What Is the Dearborn River in Montana Like?

This river’s topography is varied, featuring stretches of fast-moving waters with rapids as well as calmer, meandering sections that favor fly fishing. The river passes through canyons, alpine meadows, and prairie lands, providing a diverse habitat for a range of trout species.

Once it hits the prairies, it flattens and only has small whitewater pockets. However, the lower section that starts at the Highway 434 Bridge becomes harder to access as it flows through private property.

Type of Fish in the Dearborn River

Rainbow, cutthroat, and brown trout are most common on this smaller freestone river. The cutthroat trout and rainbow trout predominate in the upper part of the river. These fish will generally average 10 to 16 inches long.

In the lower part of the river, you will find brown trout. These are somewhat larger with the potential to catch a trophy-sized fish.

Dearborn River Trout Fishing Map

Map of the best fishing spots and access points on the Dearborn River in Montana.

Get Directions to the Fishing Access Points shown above with the DIY Fly Fishing Map

Click map icons to get driving directions to fishing access points and real-time stream flow data.

Best Places to Fish the Dearborn River

The Dearborn River offers diverse fly fishing experiences across three distinct stretches. Each section has unique characteristics and fish habitats.

Upper Dearborn River

The upper reaches of the Dearborn River are characterized by fast-moving waters and a rugged landscape. Anglers will find ample opportunities to catch native cutthroat trout among the various pools and riffles. Access can be challenging, requiring a hike or a high-clearance vehicle, but the serene beauty and potential for thrilling catches are significant draws.

  • Access Points: Dearborn Trailhead, Forest Service Trail #206
  • Target Species: Cutthroat trout
  • Best Flies: Stoneflies, Caddis, high-visibility dry flies

Middle Dearborn River

Anglers will discover the middle section of the Dearborn River offers a mix of meandering flows and moderate rapids early in the season. The water here has a more gentle gradient and can be accessed via MT 434 and MT 200. Below the MT 434 bridge there is about 40 miles of river most of which flows through private land. Wade access is limited to up and down stream of bridge crossing. This stretch provides good opportunities for rainbow and brown trout.

  • Access Points: Dearborn River High Bridge (MT 434), MT 200 bridge
  • Target Species: Rainbow trout, brown trout
  • Best Flies: Caddis, stonefly and mayfly patterns, streamers

Lower Dearborn River

As the river approaches its confluence with the Missouri River, the lower Dearborn slows down, creating deep pools and runs perfect for fly fishing. Accessibility to this 19-mile section is limited to floating. This stretch is known for larger brown trout.

  • Access Points: US 287 bridge
  • Target Species: Large brown trout
  • Best Flies: Woolly Buggers, Mayflies, Soft Hackles

Floating the Dearborn River

Floating the Dearborn River lower canyon below US 287 provides great fly fishing for rainbow and brown trout.

Many visiting fly fishermen opt to float the lower Canyon section of the Dearborn River in hopes of hooking up with one of the large browns that reside there.

The float season is very short, typically from the 3rd Saturday in May through mid-late June. This narrow window offers the right combination of safe flows, clear water, and good fly fishing. The ideal stream flow for a float trip is from 500 to 800 cfs.

Best Time to Fish the Dearborn River

Fly fishing on the Dearborn River peaks from late spring to early fall. Key times include:

  • Spring (May to June): Melting snow from the mountains swells the river, and as the flow stabilizes, conditions become ideal for fly fishing.
  • Summer (July to September): Warm weather brings prolific hatches, with mornings and evenings being the most productive times to fish.
  • Fall (October): Cooler temperatures bring out vibrant foliage, and the river’s lower flows may pose a challenge, yet this is when larger fish can often be caught.

Stream Flow and Current Conditions

Be sure to check the stream conditions before heading out to fish the Dearborn River. The USGS stream gauge near Craig, MT provide a good indication of current conditions.

The graph below shows the stream flow (discharge) for the past 7-days. If flows are considerably above or below historical norms (yellow triangles on the chart) then fishing conditions maybe not be ideal.

Dearborn River near Craig MT

  • Streamflow: 179 ft³/s
  • Gage height: 3.92 ft
Streamflow GraphGage height Graph

Best Flies for Dearborn River

The fish are not too picky in the Dearborn. Anglers can expect consistently good fly fishing with large attractor dry flies and dropper nymphs. Stoneflies are abundant on the Dearborn River and solid hatches of Salmonflies and Golden Stones keep these fish looking up throughout the season.

Many anglers do well using large streamers on the lower river when hunting larger brown trout.

Here is a list of general fly pattern recommendations for the Dearborn River:

Dry Flies

  • Yellow Sally (#12 – 16)
  • Yellow Humpy (#10 – 18)
  • Parachute Sulphur (#14 – 18)
  • Parachute Adams (#12 – 22)
  • Elk Hair Caddis (#8 – 16)
  • Yellows Stimulator (#8 – 14)
  • Chernobyl Ant (#8 – 12)


  • Pheasant Tail (#12 – 20)
  • BH Hare’s Ear (#12 – 20)
  • Rainbow Warrior (#14 – 22)
  • Pat’s Rubber Legs (#4 – 12)
  • Golden Stonefly (#6 – 10)
  • Tellico Nymph (#12 – 18)
  • WD40 (#16-20)


  • BH Wooly Bugger (#2 – 6)
  • Sculpzilla (#4)

Essential Fly Fishing Gear

The gear required for a successful trip includes a fly fishing rod, reel, line, and a selection of tools and accessories. A 9-foot, 5-weight fly rod is typically used for the varied conditions of the river, although you may want a 6- or 7-wt if you plan to float the lower canyon. Here’s a basic checklist:

  • Rod: 9 ft, 5 wt
  • Reel: Matched to rod weight
  • Line: Weight-forward floating
  • Leader: 9 ft, 4X
  • Tippet: 4X & 5X
  • Accessories: Nippers, forceps, fly floatant, and strike indicators

Dearborn River Fishing Report

Area fly shops, guides and websites that can provide a Dearborn River fly fishing report and update on current conditions are listed below:

Fishing Regulations

The state of Montana requires that all people who are 12 years of age and older have a valid fishing license. There are resident and non-resident sport fishing licenses available.

You can purchase a Montana state fishing license and learn about the most current regulations through the Montana Fish, Wildlife & Parks.

Trip Planning Tips

The nearest major city to the Dearborn River is Great Falls, Montana, located about 100 miles away. Great Falls offers various lodging options, restaurants, and fly fishing shops to meet your needs.

  • Lodging options near the Dearborn River are limited due to its remote location. Here are a few choices:
    • Lodges and cabins: Several lodges and cabins cater to anglers, offering comfortable accommodations and access to the river.
    • Camping: Campgrounds are available near the river, but be aware of regulations and permit requirements.
    • Staying in Great Falls: While not ideal for daily commutes, staying in Great Falls offers more variety in lodging options.

Looking for more places to fish? Check out our DIY Guide to the Best Fly Fishing in Montana