Clark Fork River, Montana

Vanessa Locampo
Last Updated: February 27th, 2023

The Clark Fork is one of the most treasured rivers in Montana. It stretches across the state and into Idaho, running for approximately 310 miles along Interstate 90.

Beginning near the historic town of Anaconda, the river has a fascinating history and marks one of Montana’s primary locations for trout fishing.

What Is the History of the Clark Fork River?

history of the clark fork river

The Clark Fork River has been vital to the existence of several Native American tribes in the area for hundreds of years. In the 19th century, the Lewis and Clark Expedition trekked through the basin, eventually naming the river after explorer William Clark.

Rancher and explorer John Francis Grant built his home near the river in the 1860s and built the first irrigation system, using water from the river in the running of his ranch. This would later become the famous Grant-Kohrs National Ranch Historic Site.

From the 1880s onwards, the Clark Fork became littered with heavy metal residue from the nearby towns of Butte and Anaconda, famous at the time for their industrial mining and smelting operations. The damage from the pollution was so great that the river was nearly destroyed.

In 1908, a flood washed millions of tons of toxic particles into the river, causing widespread pollution that affected the soil and groundwater for 12 miles.

To address the damage, the Anaconda Settling Ponds were set up to catch mining waste. The river today is starkly different from what it once was and is nearly free of all heavy metals.

As such, it’s a symbol of healing and restoration.

Clark Fork River Geography

clark fork river geography

The Clark Fork River is located in western Montana and northern Idaho. The river begins near the town of Butte, Silver Bow County, at the convergence of Silver Bow Creek and Warm Springs Creek.

It then travels north and northwest for around 310 miles before entering Idaho’s Pen Oreille Lake. The Clark Fork then becomes the Pen Oreille River until it reaches the Columbia River.

The most prominent tributaries of the Clark Fork are the Blackfoot, Bitterroot, St. Regis, and Flathead rivers. The mountains and valleys surrounding the river are some of the most beautiful in the region, housing wildlife preserves, national forests, and the famous Glacier National Park.

The Clark Fork is one of the longest rivers in Montana and is thought of as the headwaters of the Columbia River Basin.

It provides food and shelter for several wildlife species and serves as an integral part of the local ecosystem. Among other creatures, river otters, muskrats, beavers, geese, ducks, and kingfishers are often spotted in and around the river.

Throughout the Deer Lodge Valley, the river is used by ranchers and farmers for growing hay and watering livestock. It is also a site of recreation, attracting outdoors enthusiasts and anglers to enjoy its serene waters.

Clark Fork Watershed Stats

clark fork watershed stats

  • Covers 14 million acres
  • Comprises 28,000 miles of rivers and streams
  • Supports 350,000 people
  • Sustains agricultural operations via irrigation water
  • Provides community drinking water from ground and surface water sources

What are the Activities and Attractions Around the Clark Fork?

The Clark Fork Valley is home to a variety of geological formations, picturesque landscapes, wildlife species, and thriving communities. There’s always something to do, in and around the river!

From fishing and river rafting to playing golf and visiting historic sites, the Clark Fork is the center of endless recreational opportunities.



The most popular activity along the Clark Fork River is fishing. Rainbow, cutthroat, and brown trout are abundant across many sections of the river.

According to Big Sky Fishing, the best place to fish is between the headwaters and the confluence with the Flathead River, near the community of Paradise, Sanders County.

At its origin, the Clark Fork River is narrow enough to jump across without getting wet. But after Missoula, it broadens into one of the state’s widest rivers.

Both ends make for a great fishing experience, depending on what your style of fishing is.

Anyone over 15 years old must obtain a Montana fishing license before fishing from the river.

Water Activities

water activities

Along with fishing, the Clark Fork lends itself to other water activities like rafting and kayaking.

You can start rafting using small inflatable rafts and kayaks near the river’s origin in the Warm Springs Wildlife Management Area, but this section has slow water for the first 20 miles.

By the time the river reaches Missoula, the flow is much faster. There are a few white water rafting and general river tours you can take along the river in this section, including those that run through Alberton Gorge.

This section of the Clark Fork also happens to be one of the most scenic and is a popular location to simply relax and enjoy the view of the river. 

Grant-Kohrs Ranch National Historic Site

Originally established at Cottonwood Creek in 1862 by John Grant, the Grant-Kohrs Ranch National Historic Site is an ode to the Western cattle industry.

Today, the main house of the ranch and other significant buildings are preserved in an effort to maintain the ranch’s legacy.

Visitors will discover the original furnishings of the main house, along with the blacksmith shop, horse barns, cattle sheds, and bunkhouse.

There is also an educational visitor center on the premises, plus picnic tables where guests can admire the cattle that continue to graze in the area to this day.

There are guided tours on offer throughout the years, plus ranger-led activities like cowboy talks and blacksmith demonstrations that will immerse visitors in Western culture.

On the ranch, there are seven miles of walking trails, where visitors are likely to spot some of the 35 species of mammals that reside in the area.

Old Jail Museum

Located in the town of Thompson Falls, the Old Jail Museum is a treat for history buffs in the Clark Fork Valley. Once the county jail and residence of the sheriff, the building now preserves local history through exhibitions of fascinating artifacts.

The museum displays information about settlers and pioneers who explored and farmed the area, educating visitors about the early development of Thompson Falls.

Inside, you will find rare photographs of people and events that played a significant role in the growth of Sanders County.

The museum is open daily between Memorial Day and Labor Day.

River’s Bend Golf Course

River’s Bend Golf Course offers nine holes of stunning terrain characterized by lush trees and river landscape.

Located in Thompson Falls, the course regularly holds exciting events and tournaments and runs an on-site shop where you can buy everything you need for a day on the green.

The course is specifically designed to bring golfers back to the clubhouse every third hole. After golf, you can recharge in the bar where a variety of beer and wine is served.

River’s Bend is open seasonally from 8 a.m. to dusk every day.

Cabinet Gorge Dam Overlook

For an unparalleled view of the Clark Fork River and its scenic surrounding landscape, head to the dam overlook near the Montana and Idaho state line.

The overlook also provides stellar views of the Cabinet Gorge Dam which, together with the Noxon Rapids Dam 10 miles upstream, provides electricity to over 200,000 households in the area.

The lookout has on-site interpretive signs which reveal tidbits of information about the construction of the Gorge Dam and Glacial Lake Missoula.


With ample sections of natural beauty, the Clark Fork Valley offers multiple opportunities to camp by the river and take in Montana’s famous starry nights.

The Two Rivers RV Park and Campground is located on the Cabinet Gorge Reservoir in Noxon and has several RV sites, tent sites, and walking trails.

On the grounds, campers will also be treated to free Wi-Fi, a laundromat, restrooms and showers, a dump station, ice, and vending machines. There is also a sand volleyball court and a community fire pit for some extra fun.

Other campgrounds to check out along the river bank include Big Eddy Recreation Area, east of the Idaho Border, South Shore Recreation Area on the south end of Noxon Rapids Dam, Thompson Falls State Park, and Finley Flats Recreation Area at the Noxon Reservoir.

While camping at these parks, and in other locations along the river banks, you will have access to wonderful fishing, water sports, and nature photography opportunities.


Many of the recreation areas along the Clark Fork provide networks of hiking trails that allow travelers to explore the local area.

The destinations with the best opportunities for hiking include Thompson Falls State Park and Finley Flats Recreation Area.

The hiking trails in the valley deliver breathtaking views of the Clark Fork River, dense pine forests, grassy plains, and the majestic mountains that border the region.

River Facts

river facts

  • The Clark Fork River is the largest river in Montana by volume.
  • The river, from its confluence near Warm Springs to the former site of the Milltown Dam, east of Missoula, became a government Superfund Site in 1992.
  • Work began in 2018 to stabilize the eroding banks of the river near the Grant-Kohrs Ranch National Historic Site, and re-vegetate the riparian habitat.


  • How deep is The Clark Fork River? Approximately five feet
  • How long is The Clark Fork River? 310 miles (500 km)
  • How wide is The Clark Fork River? n/a
  • Where does The Clark Fork River start? Silver Bow Creek, Butte, Montana
  • Where does The Clark Fork River end? Lake pend Oreille, Bonner County, Idaho
  • Which way does The Clark Fork River flow? Northwest


The Clark Fork River, Montana, runs for more than 300 miles into northern Idaho, offering endless opportunities for fun and recreation along the way.

More importantly, the river’s watershed supports thousands of people in the area and serves as a fundamental part of the local ecosystem. 

While the river was once tarnished with pollution from the mining towns nearby, it is now largely clean and restored to its original beauty—a testament to how much of an environmental difference humans can achieve when they work together with a common goal.

Have you ever visited the Clark Fork River, or any of the nearby destinations? Let us know in the comments below!


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About The Author

Vanessa Locampo

Vanessa is an Australian-based freelance writer and editor with a BA in Creative Writing. She’s passionate about creating travel content that inspires her readers to take a leap of faith and power through their bucket lists. When she’s not writing (with her border collie asleep at her feet), she’s devouring books, exploring the world, or planning her next trip.

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