Fly Fishing Idaho’s Lesser Known Rivers. The Warm River.

Fly Fishing Idaho

Part V of VThe Warm River

When fly fishing Idaho, most people refer to the Warm River as the place where you put your boat in to float the Henry’s Fork of the Snake River down to the Ashton Bridge.  However, what people don’t realize is that the Warm River has some of the same beautiful trout that the is common in Idaho’s famous waters.


The River

Warm River is a spring fed river.  That makes this 26 mile live    water extremely clear with water temperature at 50 degrees year around providing excellent habitat for native trout.  The Warm River rises in the Caribou-Targhee National Forest, along  the western border of Yellowstone National Park.  In its upper reaches, it fishes like a small mountain stream.  At the Warm River Spring, it dramatically changes into something that most would call a modest river.  Approximately 200 cubic feet per second of that 50 degree water gushes out of an ancient volcanic aquifer and cascades down a hillside, greatly expanding the stream.  From this point down to its junction with the Henry’s Fork, the Warm River averages 25 to 50 feet wide and is excellent to wade and fish.


One of the allures of the Warm River is that most of it runs through national forest land.  While portions of it flow through a difficult-to-access canyon – an enticement for anglers who like to hike – other reaches are readily accessible via Forest Service roads.

The Warm River is located about 25 miles northeast of Ashton, Idaho.  To access the river from Ashton, take Highway 47, the Mesa Falls Scenic Byway, east then north and you will run right into the Warm River Campground.  To access its upper stretches, continue on highway 47 until you hit the Bear Gulch area.  At this junction take the FR 367 north which will keep you right along the river.  You will then hit FR 150 which takes you even further up river to the steam like section of the Warm River.

On the upper River, the Pole Bridge Campground offers a place to stay for those who like smaller water.  At the lower end, the popular Warm River Campground provides stream-side sites on the larger water below the spring.  There is also a trail built on an abandoned rail line that runs upstream from the camp offer anglers less fished waters.


Like the Henry’s Fork, the Warm River originally supported native Yellowstone cutthroat.  Today, visitors to the Warm are more likely to catch wild or stocked rainbows, with wild browns, brookies, and mountain whitefish (Yetter’s favorite).  In addition to resident fish the Warm River also supports spawning runs of rainbows and browns coming up from the Henry’s Fork.

Along with standard western attractors, anglers should take a supply of drake patterns, PMDs, and Blue-Winged Olives, along with various caddisfly, midge, stonefly, and hopper patterns.  If you are prepared for the Henry’s Fork, you will do fine on the Warm River.

For Winter Fishing season (Dec 1st – March 31st)  on the Warm River the following are great patterns:  #16 bead head Pheasant Tails, Pat’s Rubber Legs , bead head prince nymphs #10.

As with the rest of this series of posts – Fly Fishing Idaho’s Lesser Known Rivers – we will do a follow up this year and report on our success.



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2 Responses to “Fly Fishing Idaho’s Lesser Known Rivers. The Warm River.”

  1. Jonathan Sage Says:

    While visiting SE Idaho (Driggs area) and itching to do some out-of-area flyfishing, I located this post on the Warm River and followed the suggestions/directions and yes….what a delightful river to wade and fish. After a couple days exploring both the upper section and the lower section I was hooked. Easy wading with lots of early morning fish rising to the Mayfly hatch.

    Took a friend for her first fly fishing experience and she hooked and landed her first rainbow in about 15 minutes (after expert casting lesson from me….ha ha) . She
    managed several fish and lots of LDR’s. Very fun day on the Warm River.

    This article was dead-on as far a directions
    and described a river that locals like to keep
    to themselves. The mountain section is awsome with many aggressive brookies and some rainbow loving the extended body PMD’s and other similar patterns.

    Thanks for a great article!


  2. Jack Wolbach Says:

    You can stay in the Warm Springs campground and watch osprey dive in the Warm river. Fish the Warm during the morning risers, and fish the Henry’s Fork in the evening during caddis hatches. The Robinson Falls River and other streams are close by. What a place!


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