The Beaverhead River, Montana

Mark Barnett
Last Updated: February 27th, 2023

The Beaverhead River in Montana starts out at Clark Canyon Dam, near Dillon, Montana, and flows for 80 miles to its eventual confluence.

From the dam to Three Forks, where the Beaverhead joins with the Big Hole and the Ruby River to form the Jefferson River, it stretches for 69 miles.

The river banks are lined with willows, cottonwood trees, and grass, and the fifteen miles or so of water that twists and turns from Clark Canyon Dam to Barrett’s Diversion is a renowned gateway to some of the best trophy trout fishing in the country. Certainly, this upper section of the river is the most famous.

Needless to say, trout fishing is one of the prime reasons people seek out the Beaverhead River.

To get there take the I-90 towards Whitehall for 60 miles then continue along Highway 55/41 for another 55 miles and on through Twin Bridges to Dillon.

The History of the Beaverhead River in Montana

Lewis and Clark’s main expedition camped along the Beaverhead River at Beaverhead Rock, which is now in an area designated as a state park south of Twin Bridges on Highway 41.

Beaverhead Rock marks the meeting of the expedition team with the Shoshone tribe who helped them track safely across the mountains.

Lewis & Clark actually used the best part of a quarter of their expedition in Montana and their route at some points included the Jefferson and the Beaverhead River as they made their way across the Southwestern regions of Montana.

The Beaverhead today has not changed that much since Captain Lewis described it in 1805.

The Beaverhead River’s Access Points

beaverhead river’s access point
Image: Coreyk23

One of the easiest points of access for the river is off I-15 at Exit 44 for the dam. This will also likely be one of the busiest during certain times of the year.

If you want Grasshopper Creek to take Exit 52, and Exits 62 and 63 take you towards Dillon.

Many potential anglers who want to do a spot of sizing up first can get some idea of its scope by heading along the secondary road past Pointdexter Slough south of Dillon, close to the Highway 278 junction.

This road leads all the way up to the dam and across the river, sometimes joining with an old-looking Highway 91.

Poindexter Slough is a 4.7-mile long channel along the valley-bottom of the Beaverhead River. It is fed through a mix of groundwater and Beaverhead River flow.

The lower 3 miles or so here are on a FWP Fishing Access Site, and this one provides a rare publically accessible spring creek.

Fishing the Beaverhead River

The Beaverhead River is one of the premier brown trout fishing rivers in Montana—that much we know.

On top of that is the fact that these waters consistently produce more brown trout—and we mean on the large side–than any other river in Montana!

The well-known stretches of the river that everyone cannot wait to get stuck into are reportedly on the challenging side.

Take the upper stretch between Clark Canyon Reservoir and Barrett’s Diversion Dam. Here there is heavy pressure, large yet finicky brown trout, small nymphs, and frequent difficult water conditions.

Add to that the twisting nature of the river and you have quite an experience ahead—although not without rewards. The river is renowned for the real large brown trout.

A common brown trout, particularly on the upper section of the river, can average something like twelve to fifteen inches.

Access to the river between Clark Canyon Dam and Barrett’s Dam couldn’t be easier. Numerous fishing access sites are available, including both private and public land bordering the river.

The early-ish months of March, April, and May are the most likely time to find exceptional fishing.

Camping along the Beaverhead River

Beaverhead River Campground and RV Park in Dillon would be an obvious choice here.

Located off I-15 somewhere between Butte and Idaho Falls, this facility—like any decent campground—is a gateway to a gamut of outdoor recreation options.

The campground also rather luckily sits along 800 feet of the river, and if you fancy checking out some local heritage the Beaverhead County Museum is a five-minute drive from this park.

This is a well-maintained campground ideal for the whole family. The amenities at the park include pool access, 24/7 laundry, restrooms, Wi-Fi access, and a few other features like mini-golf

Other Accomadations

Given the close proximety of Dillon, Montana to the Beaverhead River, if you are looking for lodging the town may be your best bet.

Thankfully, the town has several accomadation options for you to check out when planning your trip to the Beaverhead River.

Other Recreation and Tourism along the Beaverhead River

tourism along the beaverhead river

The Beaverhead County Museum is an option for some recreation of a slightly different nature.

Although what was the town’s first flush-toilet outhouse is considered by many as the museum’s showpiece, this local downtown Dillon museum also features some excellent displays related to the Lewis and Clark expedition’s findings in the region, as well as agricultural history.

Back to the more outdoor-oriented pursuits, we can begin with the start point of the river, Clark Canyon Dam & Reservoir serving as something of a recreation point in the area.

It dates back to the mid-1960s and is a popular picnic spot with a boat launch and a couple of campgrounds.

With its easy access and quality fishing options, the reservoir has long been a favorite of local anglers–including ice fishing in the winter months—as well as boaters and all manner of other water sports enthusiasts.

Not too far out from Dillon, Clark Canyon is an ideal day-use destination.

Along the stretch of the Beaverhead from Clark Canyon Dam to Dillon, the water is a grade I-III, 21-mile sweep of white water. If you already happen to have a bit of white-water rafting or rapid kayaking experience under your belt, this run of the river could be right up your street.

When considering the hiking options in the regions of the Beaverhead River it wouldn’t be possible to do so without first coming across the Beaverhead Trails Coalition, a group of volunteers who managed to raise a ton of money to purchase the almost 800 acres of land across the river.

They are working continuously on putting trails together along with partners like the YMCA and if you head to the YMCA on Swensen Way you can take advantage of the paved and the gravel trails on offer.

The Dillon High Trails connect wetlands and contain the Blacktail Meadows Fishing Access Point as well as a kids’ pond.

The trailhead is on Ten Mile Road, just two miles out of downtown Dillon. The route is used by hikers and bikers and is a combination of cow trails and old two-tracks.

There is some decent single-track trail that seems to fade in and out, and you’ll soon notice that horses also use the trails, which are open to all non-motorized use.


The Beaverhead River is arguably one of the finest trophy trout rivers in Montana.

It is a pure and winding river surrounded by scenic areas, and it attracts high numbers of visitors to the Dillon boundaries and beyond. Many visitors are undoubtedly in search of the large brown trout the river is famous for.

Aside from that it runs through scenic areas and supports the extensive recreation already available in those regions.

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About The Author

Mark Barnett

Mark Philip is a writer and lifestyle enthusiast from the Midlands in the U.K. With a background in martial arts and fitness, Mark headed out to Bangkok, Thailand where he now lives and works. Mark has authored e-books, articles, and blogs across a wide range of topics for commercial, educational, factual, lifestyle and leisure-based purposes.

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