Top 3 Fly Fishing Rivers in Idaho

Several of the most famous fly fishing waters in the country flow through Idaho. The eastern border with Montana and Wyoming is geographically defined by the Continental Divide where the cold clean headwaters of the major Northwest rivers flow off the Rocky Mountains. This region provides anglers a lifetime of trout fisheries to explore.

Here is an introduction to the 3 best fly fishing rivers in Idaho:

1. The Middle Fork of the Salmon River
2. The Henry’s Fork of the Snake River
3. The South Fork of the Boise River

Middle Fork of the Salmon River

Species

• Cutthroat Trout
• Rainbow Trout
• Brook Trout
• Bull Trout
• Chinook Salmon (no fishing season)
• Steelhead (no fishing season)
• Mountain White Fish

Region: Central Idaho Wilderness

The Middle Fork of the Salmon River flows 109 miles from the north end of the Sawtooth Mountains (near Stanley Idaho) to its confluence with the Main Salmon River (near Salmon Idaho).  The Middle Fork cuts through the 2.3 million acre Frank Church River of No Return Wilderness area, and is one of the most pristine wild and scenic rivers in the country.  The river flows through the Impassable Canyon, the third deepest canyon in the United States. Becuase of its remote location, it’s important to consider access to the river. The best way to experience Middle Fork Salmon River fishing is to float from Boundary Cr (or Indian Cr later in the season) either on a private trip with experienced boaters or on a guided Idaho fly fishing trip. The other ways to access the Middle Fork are to hire a backcountry air service to fly you into one of the few airstrips along the river, or to take the trails on foot or horseback (20 miles minimum to get to the river) from the trailheads surrounding the edge of the wilderness boundary.

About the River

The Middle Fork has been a catch & release, single barbless hook, wild fishery since 1973. The Middle Fork is famous for dry fly fishing along it’s 100+ miles of wild river. There are 3 major tributaries (Big Creek, Camas Creek and Loon Creek) that are also productive cutthroat and rainbow fisheries.  There are wild Chinook and Steelhead that travel over 900 miles to and from the ocean to spawn on the Middle Fork. The Middle Fork is home to one of the healthiest populations of native westslope cutthroat trout in America. Their trinomial name, Oncorhynchus clarkii lewisi, comes from the famous western explorers who passed along the Salmon River in 1805 in seach of a safe westward passage through the Northern Rockies. The trout of the Middle Fork of the Salmon are very surface oriented, producing some of the best dry-fly fishing in the world. A comprehensive guide to which flies attract these incredible fish can be found here.

Fishing Regulations for the Middle Fork of the Salmon River.

Middle Fork Salmon River Fly Fishing Trips with Solitude River Trips

Our Summer Fishing Season is from July to August, and our Fall Fishing Season will often run from September into October. Salmon River Idaho Summer Fly Fishing trips are unforgettable – you will fish the largest variety of stimulating fly water of anywhere in the West. 

Fall Fly Fishing the Middle Fork of the Salmon River offers some of the best fly fising in Idaho. The temperature cools, the water gets lower and slower, and we have the whole Wilderness nearly to ourselves. We offer Drift Boats or custom fishing rafts during our summer season, and Fishing Rafts only during our smaller September trips. 

We also offer mild to wild Middle Fork Salmon River rafting trips throughout the summer and into early fall.

Henry’s Fork of the Snake

Species

• Brown Trout
• Rainbow Trout
• Cutthroat Trout
• Mountain Whitefish

Region: Eastern Idaho

Some of the best fly water in the country flows westward from the Teton & Yellowstone Mountains, where ribbons of aquatic life stream into the desert of Eastern Idaho. The Teton River, The Henry’s Fork and the South Fork of the Snake (ordered from smallest to largest) are the three major headwaters of the mighty Snake River. Their confluence is near Rexburg, Idaho. The most prestigious is the Henry’s Fork, although a trip to Eastern Idaho mandates an adventure on each of these unique fly waters (as well as Henry’s Lake).

About The River

Offering some of the best fly fishng in Idaho, the Henry’s Fork is famous for large Brown and Rainbow trout, thick hatches, and technical presentations (dry and subsurface). There are 3 major sections of the Henry’s Fork: Henry’s Lake to Island Park Reservoir (including the confluence with Big Spring), from Island Park Reservoir to Mesa Falls, and below Mesa Falls.  Of the 130 miles between Henry’s Lake to the confluence with the Snake River, the middle section (including Box Canyon and Railroad Ranch) is the most acclaimed.

Rules & Regulations on Henry’s Fork of the Snake.

South Fork of the Boise

Species

• Rainbow Trout
• Bull Trout
• Whitefish
• Brook Trout (above Anderson Ranch Reservoir)
• Kokanee (above Anderson Ranch Reservoir)
• Smallmouth Bass (near confluence with Arrowrock Reservoir)

Region: Southwest Idaho

The headwaters of the South Fork of the Boise River flow off the south and west slopes of the Sawtooth Mountains and the Smoky Mountains.  The upper and lower sections are separated by Anderson Ranch reservoir.  

About the River

No list of the best fly fishing rivers in Idaho would be complete without the South Fork of the Boise. The most popular and productive section for fly fishing is the tailwater between Anderson Dam Reservoir and the Blacks Cr. Bridge.  From the dam to Danskin Bridge provides easy road access.  The canyon section below Danskin Bridge provides some fantastic and less pressured trout water, but can only be accessed by a committing and challenging float. The South Fork of the Boise doesn’t have the prestige of Idaho’s traditionally acclaimed trout waters (such as Henry’s Fork, Silver Creek, South Fork of the Snake, The Middle Fork if the Salmon, or Kelly Creek), but this cold tailwater holds some of the largest rainbows in the state for a river of its size, making it a top fly fishing river in Idaho.  Along with the Owyhee River, this is a popular day trip destination for Boise anglers.

Rules & Regulations on the South Fork of the Boise.

Other Notable Fly Fishing Waters in Idaho

While we’ve spotlighted three of our favorite rivers, Idaho boasts many more waters worth exploring:

• Silver Creek – A world-famous spring creek near Sun Valley, known for technical fishing and large brown trout.
• South Fork of the Snake River – A blue-ribbon trout fishery with high fish counts and spectacular canyon scenery.
• Big Wood River – Great dry fly fishing near Ketchum and Hailey.
• St. Joe River – A scenic freestone stream in North Idaho with eager cutthroat.
• Lake Coeur d’Alene – Stillwater fishing for trout and bass with a mountain backdrop.

When Is the Best Time to Fly Fish in Idaho?

Idaho’s fly fishing season typically runs from late spring through fall, though exact timing varies by river and elevation:

• Spring (April–May): Best for tailwaters like the South Fork Boise.
• Summer (June–August): Prime time for most rivers, with peak hatches and good flows.
• Fall (September–October): Cooler temps and aggressive feeding make this an excellent window for big trout.

High-elevation rivers like the Middle Fork typically become accessible in early July, once runoff subsides.

What Species Can You Catch Fly Fishing in Idaho?

Idaho is home to a variety of native and wild trout species:

• Westslope Cutthroat Trout – Common in wilderness streams like the Middle Fork.
• Rainbow Trout – Found in rivers, creeks, and lakes across the state.
• Brown Trout – Present in spring creeks and lower elevation rivers.
• Bull Trout – Protected native species; catch-and-release only.
• Brook Trout and Whitefish – Often found in smaller tributaries.

Do I Need a Fishing License to Fly Fish in Idaho?

Yes. All anglers 14 and older must have a valid Idaho fishing license. Non-resident and short-term licenses are available. Be sure to check Idaho Fish and Game regulations for river-specific rules, seasonal closures, and gear restrictions.

Some rivers—like the Middle Fork of the Salmon River—are fly fishing only and strictly catch-and-release. Know before you go!

Gear & Fly Fishing Tips for Idaho

• A 9-foot 5-weight rod is a versatile setup for most Idaho waters.
• For spring creeks like Silver Creek, consider a lighter rod and long leaders.
• Flies to pack include Stoneflies, PMDs, Caddis, Hoppers, and Green Drakes.
• Match the hatch, especially on technical rivers like the Henry’s Fork.
• Bring waders, but some rivers fish well from drift boats or by wet wading in summer.

Why Idaho is a Fly Fishing Paradise

Idaho offers a stunning diversity of fly fishing options, from remote wilderness rivers to iconic spring creeks. Whether you’re drawn to the rugged solitude of the Middle Fork Salmon, the technical challenges of Henry’s Fork, or the canyon beauty of the South Fork Boise, Idaho’s trout fisheries are second to none.

For anglers seeking the best fly fishing in Idaho, these rivers offer an unforgettable experience surrounded by wild landscapes, healthy fish populations, and endless adventure.

Contact Us at Solitude River Trips for More Information

Solitude River Trips offer the most comfortable, convenient, and unforgettable wilderness Middle Fork Salmon River fly fishing and Idaho whitewater rafting experiences in North America. We are ready to get you out on the Middle Fork of the Salmon River! Our 6-day trips are designed to provide families, friends, lovers, or solo travelers with the most unforgettable and high-quality adventure vacation of their lives.