Montana continues to rank as one of the top destinations in the world for fly fishing—and it’s easy to see why. Anglers from across the globe flock to Big Sky Country to cast their lines into the blue-ribbon waters. One of the most iconic stretches is the Gallatin River, which winds its way just outside of Big Sky, Montana.

Fly Fishing on the Gallatin

The Gallatin River

Whether you're new to fly fishing or have years of experience under your belt, fishing the Gallatin is unforgettable. Gallatin River Guides reports that the stretch between Spanish Creek and Yellowstone National Park—about 40 miles—holds around 2,500 to 3,000 wild trout per mile.

Fish Species You’ll Find in the Gallatin

The Gallatin River holds a special place in the hearts of many, famously featured in the iconic movie "A River Runs Through It." This stunning backdrop, recognized by anglers and movie buffs alike, offers an incredible setting for a day on the water. If you're looking to cast a line here, it helps to know what you might find swimming beneath the surface.

Here are a few of the most common catches:

 

Rainbow Trout in the Gallatin River
 
 
Rainbow Trout:

Bright, aggressive, and known for their acrobatics, rainbow trout are a favorite for many anglers.

 

 
 
 
 
 

 

Westslope Cutthroat Trout
 
 
Westslope Cutthroat Trout:

 This native species is another sought-after fish in the Gallatin River. It is beloved for its distinctive orange-red slash along the jaw.

 

 
 
 
 
 

 

Mountain Whitefish
 
 
Mountain Whitefish:

While not as often targeted, whitefish are plentiful in the Gallatin and put up a fun fight.

 

 
 
 
 
 

 

Brown Trout
 
 
Brown Trout:

While not a native species, brown trout are a prized catch for experienced anglers. 

 

 

 

 

 

You can learn more about each of these species by visiting the Montana Field Guide or checking the fish ID section at Montana Fish, Wildlife & Parks.

 

 

Tips for a Successful Day on the Gallatin

 

Before you hit the river, it’s smart to check the current Gallatin fishing report or hire a local guide. The river’s terrain can be tricky, and conditions change rapidly, so having expert knowledge can make all the difference.

Peak fishing season runs from June through October, making summer and early fall the ideal time to hit the river. 

Fishing licenses are required by law in Montana and can be purchased at local gas stations and fly fishing shops in Big Sky. Options include a 2-day, 7-day, or seasonal license. A separate license is required for fishing within the park boundaries of Yellowstone National Park. Most Big Sky fly shops will also sell Yellowstone National Park (YNP) licenses.  Explore the Yellowstone National Park website for more details on fishing access. 

Catch-and-release is the standard here, so brushing up on proper techniques helps protect the fishery for generations to come. Local guides and shops offer insights into river etiquette, regulations, and best practices. You can also learn more in our Catch-and-Release article. 

 

 

 

Where to Gear Up and Find a Guide

The best way to experience the Gallatin—or any river in Montana—is to connect with the people who know it best. These trusted local outfitters and fly shops offer gear, trips, and guidance:

 

 

 

A Year-Round Fly Fishing Destination

While summer and fall offer peak conditions, fly fishing on the Gallatin River is a year-round opportunity. Whether you're casting dry flies in July or nymphing through snowy banks in January, the beauty and serenity of the river never fade.

So, if you're planning a trip to Big Sky, Montana—don’t forget your rod. Once you experience the Gallatin, you'll understand why so many anglers get hooked for life.