Montana Fly Fishing 4 min read

DIY Guide to Fly Fishing the Kootenai River in Montana

Ken Sperry

Posted by Ken Sperry

September 20, 2017

Kootenai River Montana

If you are looking for a new and exciting fishing experience, the Kootenai River in western Montana could be a breath of fresh air. It is unlike many of the more popular blue ribbon rivers in Montana, but it provides some of the best opportunities for trout fishing in the entire region. 

In fact, some of the biggest fish ever pulled out of a Montana river have come from the waters of the Kootenai, and there are tons of opportunities to catch prize-caliber rainbow trout here.

It is also one of the largest rivers in the area, beginning in British Columbia and flowing for 485 miles through western Montana and northern Idaho before turning north again and returning to Canada.

Kootenai River

Fly Fishing the Kootenai River in Northwest Montana

The area below Libby Dam presents the best fly fishing experience, and that is the portion of the Kootenai on which we will focus this article.

While fishing the Kootenai can provide a unique and exciting experience for anglers, the river is not without its challenges. Because the waters of the river are regulated by the dam, the flows and water levels can be erratic.

Combine that with the sheer width of the the river, and it can be difficult to fish without a boat in most portions of the river. While there are some opportunities for wading along the length of the river, fishing from the boat will provide the most success in the Kootenai.

While there are some challenges and restrictions of the river, dedicated anglers may have the opportunity to catch the big one that can hang above the fireplace in the Kootenai. The state record rainbow trout was caught just below libby dam– a giant of a fish weighing 33 pounds and measuring 38 inches in length!

If you are looking more for a casual fishing trip and favor quantity over quality, the Kootenai can also provide that with approximately 1,500-2,500 catchable rainbows per mile. Running between mountains, through canyons and over falls, the Kootenai also has some of the most varied and beautiful scenery of any river in western Montana.

It may not be the typical blue sky experience of Montana fishing, but this river may have even more to offer anglers who are up for the challenge.

Kootenai River Map, Fishing Access Sites and Boat Launches

map of fishing access spots on the Kootenai River in Montana

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

Best Places to Fish the Kootenai River

The best fishing in the Kootenai will begin just below Libby Dam. This 17-mile stretch can be daunting to some anglers, as the river is very wide here and the flows can be quite fast at times.

When the water levels rise, large portions of vegetation can be flooded, and there will also be plenty of deep pools filled with trout if you are able to spot them. During early spring and late fall when water levels are lower, the river narrows significantly and there will be extensive gravel bars exposed along the banks. Because the flow of the river can vary dramatically, it is very important to pay attention to water level reports, especially if you plan to wade in.

Drifting this section in a boat will usually be the safest and most effective method, especially during the summer. A highway (Hwy 37) runs along much of this portion of the river, and there are plenty of access points available, many of which are boat ramps (shown on map above). 

There are several feeder rivers which flow into this portion, and they provide great opportunities as fish seek relief from fast currents. It can also be helpful to pay attention to seams in the middle of the river that provide pockets of slower moving water. When water levels are high, there will also be some good opportunities in the deep pools and submerged vegetation where fish will gather.

As the river moves past the town of Libby, another 33-mile stretch can present some good fishing. This area is similar to the upper portion of the river, but there are more rapids and less access points. One section known as China Rapids presents some excellent fishing opportunities in the deep pools found around the many rocks and riffles here.

Beyond this point, the river makes its way to the 30-foot waterfalls of Kootenai Falls. The area past the falls and before the Idaho border is the lowest elevation in all of Montana, and this can present some unique opportunities and surprisingly warm weather.

River Flow and Current Conditions

Kootenai River bl Libby Dam nr Libby MT

  • Streamflow: 4050 ft³/s
  • Gage height: 17.82 ft
Streamflow GraphGage height Graph

Best Time to Fish the Kootenai River

Fishing usually begins in the Kootenai in March or early April. This is the spawning period for the river’s large rainbow population, and the clear cool water will present plenty of chances.

This is also the best time for wade fishing, as the water levels will usually still be relatively low. In May and June, several hatches will begin along the length of the river, and dry fishing will begin to heat up.

As summer approaches, the water level will rise dramatically along the tailwater portions of the river. This is usually the most popular time for fishing, and rainbows will be available in abundance.

The water will still remain relatively cool even in the middle of August, and this time of year can present some real opportunities for catching some of the very large trout in the Kootenai. Water levels continue to be relatively high all the way into early September, but fishing will cool off significantly around November.

Kootenai River Fishing Tips

Spring presents good chances for streamer fishing and nymphing. Hatches in early summer mean that caddis flies are a must for this time of year. Traditional dry fishing techniques can be useful in catching rainbows in high quantity during summer. 

However, if you are hoping to catch the big one in the Kootenai, you should plan on bringing some very large streamers and sink-tip line. Most of the larger fish in the river will be caught by hopping them along the bottom.

Gear Recommendations

A 9-foot 5-wt fly rod with floating line is perfect for fishing dry flies and small nymphs on the Kootenai River. For larger nymphs and streamers a 9-foot 6-wt with a sink tip fly line makes life easier. A tapered 9-foot leader, with tippet size 3X to 6X to match the flies you are throwing, is pretty standard.

Kootenai River Fishing Reports

There are a number of area fly shops and on-line retailers that publish Kootenai River fishing reports. A few to check out are listed below.

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