Difficulty I-III
Length 17.5 Miles
Gauge Thompson River near Thompson Falls MT
Flow Range 500 - 2500 CFS
Flow Rate as of: 1 hour ago 185 [CFS]
Reach Info Last Updated 05/08/2019 5:07 pm

River Description

The Thompson is a beautiful roadside river with several short interesting sections of easy whitewater separated by realtively long sections of flat moving water. The rapids are generally located near the confluence with the Clark Fork, and upstream about 3-4 miles in an obvious section of rapids. Rapids are comparable in difficulty to the Blackfoot River, with a bit more complexity and structure. The river begins up near Highway 2 in "Thompson Lakes," and flows south through Plumb Creek Timber Co. and Lolo National Forest service lands. Although the biggest whitewater may be near the end, good paddling starts near the Little Thompson River confluence.

There are two roads paralleling the river. Thompson River Road is the main highway and runs along the west (river right) side of the river.  The river-left road is smaller and provides ample river access and scouting opportunities.  Bridges connect the two roads only at Little Thompson River and near Clark Fork.

Getting there:  The Thompson River is located in the northwest corner of Montana. It flows into the Clark Fork just east of Thompson Falls, which is west of Plains, MT along Hwy. 200.  

Rapid Descriptions

West Fork Thompson confluence

Class - N/A Mile - 10.88
Rapid Thumbnail Missing


Class - II Mile - 13.9
Rapid Thumbnail Missing


Class - II Mile - 14.26
Rapid Thumbnail Missing


default user thumbnail
12 years ago

You should see it at 1,200 or even 2,000 it gets even more fun. I think that around 2,000 it warants a class IV, and is much faster and pushier with a few log jams to avoid. It is a blast, and one of my favorite rivers in western MT. Also it can be a great warmup for Prospect Creek which is just the other side of T Falls.

Gage Descriptions

I scouted this reach at 630cfs and thought the flow looked really pleasant.  It could certainly be run lower and higher, and the flow range noted on this page is very rough, especially on the high end.

Directions Description

We have no additional detail on this route. Use the map below to calculate how to arrive to the main town from your zipcode.

No Accident Reports




article main photo

Appeal Challenging Montana Navigability Is Denied

Jason Robertson

On May 28 the U.S. Supreme Court denied an appeal by Mountain States Legal Foundation who filed a lawsuit in June 2001 alleging the 1985 Montana Stream Access Law violated their rights under the U.S. Constitution to regulate who floated over their land.

The decision thereby protects Montana's Stream access law and public rights of navigation throughout the State.

article main photo

River Recreationists Win Big in Montana!

Jason Robertson

The Missoulian newspaper reported on January 5th, 2001 that U.S. District Judge Charles C. Lovell dismissed a case brought by the Mountain States Legal Foundation challenging public recreational rights on Montana’s rivers and streams. This is a huge win for boaters and fishermen!

Paul Martzen


Matt Muir


Revision #Revision DateAuthorComment
1212212 05/08/19 Paul Martzen updated image position
1201352 05/28/12 Paul Martzen added coordinates & Mileage, added more description
1194706 03/06/09 n/a n/a
1201351 05/28/12 Paul Martzen put Karl's photo on mainpage