Clark Fork River, Montana

Clark Fork River runs through the states of Idaho and Montana. It is three hundred and ten miles long. If you consider volume, it is the biggest river in Montana. The river drains a broad region of Rocky Mountains in the northern part of Idaho and in the western part of Montana. The water is drained in the Columbia River watershed. Clark Fork flows northwest within a valley at the foot of Cabinet Mountains. It then drains into the Lake Pend Oreille in the panhandle of Idaho. Pend Oreille River is included as a part of Clark Fork as it piles up a length of four hundred and seventy nine miles through Idaho, Washington and British Columbia in Canada where the lake is drained to Columbia. The upper twenty miles of Pend Oreille is referred to as the Silver Bow Creek near Butte in Montana. It has a drainage base of twenty five thousand eight hundred and twenty square miles. The Interstate 90 runs through most of the upper route of this river to the northwest part of Missoula from Butte.

Clark Fork River cannot be mixed up with the Yellowstone River Clarks Fork in Wyoming and Montana. The Silver Bow Creek in the south west part of Montana rises within five miles of the continental divide which is near the downtown section of Butte, near the union of Blacktail and Basin Creeks. The river continues to flow northwest through a mountain valley as it passes the eastern part of Anaconda It is here that the river becomes Clark Fork near the union of Warm Springs Creek, going further northwest towards Deer Lodge. Near this Deer Lodge, the river gets the waters of the Little Blackfoot. It continues its run northwest through Western Montana, going south of Garnet Mountains towards Missoula. Clark Fork merges with the Blackfoot River, about five meals to the eastern side of Missoula.

The Clark Fork goes through a lengthy valley to the northwest part of Missoula along the northeastern edge of the Bitterroot Mountains. It runs within Lolo National Forest. It gets the waters of the Bitterroot River from the southwestern part, roughly around five and a half miles west of Missoula downtown. It also gets the waters of the Flathead River to the side of the Cabinet Range near Paradise from the eastern part. It gets the waters from the north of the Thompson River near the Thompson Falls in the southern part of Sanders County.

The Clark Fork is held by Noxon Rapids Dam to give structure to a twenty-mile long reservoir at Noxon in Montana, by the side of the Cabinet Range. Between Heron and Cabinet, the river crosses into the east section of the Bonner County which is in Northern Idaho. It then enters the northeast part of Lake Pend Oreille, about eight miles west of the state line of Montana and Idaho near the Clark Fork town.


Since the last twenty thousand years and through the ice age, The Valley of Clark Fork has laid along the south border of Cordilleran ice sheet that covers the western part of North America. The infringement of this ice sheet went to form a dam of ice on this river, forming the Glacial Lake of Missoula. It stretches along the Clark Fork River Valley through Central Montana. The regular rupture that has taken place and the reconstruction of the dam set out the floods in Missoula. These were a succession of calamitous floods that went down both Pend Oreille and Clark Fork into the area of Columbia, resulting in the forming of the topographical features of the eastern part of Washington along with the Willamette Valley in Oregon.

During the better part of the nineteenth century, the Clark Fork River Valley was occupied by the Native American Tribe of Flathead. This area was traversed in 1806 by Meriwether Lewis of the famous Lewis and Clark Expedition on his Pacific return trip. The river is actually named after William Clark from this famous collaboration. A mid section of this river in the Montana area was known earlier as Missoula River. It was commonly referred to also as Deer Lodge River by the famous Granville Stuart.

David Thompson, belonging to the North West Company, searched this region in 1809 and founded many posts for fur trading. It included the Kullyspell House at the stem of the Clark Fork River and also the Saleesh House which is near the Thompson Falls site in Montana. Thompson gave the name of Saleesh River for the complete Fork-Pend Oreille and Clark-Flathead River System. During the first half of the nineteenth century, Clark Fork River and its surrounding areas were controlled by Canadian-British North West Company and the Hudson’s Bay Company.

Clark Fork River meandered across the cattle valley which replaced bisons somewhere around the middle of the nineteenth century. It was around this time that Conrad Kohrs had bought a ranch called the Grant-Kohrs Ranch from Johnny Grant. It has become a National Historic Site and also a Federal Park.

Ever since the late nineteenth century period, many watershed regions of the Clark Fork River have been expansively excavated for minerals. It has also led to a continuous pollution problem for the stream. Much pollution has come about from the Butte copper mines and the Anaconda smelter. These polluted areas have been cordoned off as Superfund regions.
In the present day, the watershed of the Clark Fork River includes the largest Superfund location in the country. This mega site now encompasses three major regions of Milltown Dam and Clark Fork, Anaconda and Butte. Each site has been individually divided into several sub-sites which are called Operable Units. There is regular restoration work that goes on here.


When the Superfund Act came about, a large section of Clark Fork was designated as Superfund Site and a huge amount of time as well as money went into its cleaning work. The Anaconda Settling Ponds were constructed to trap mining waste before it went into the head waters and these ponds have been largely effective in trapping these heavy metals. The metals from several feeder creeks such as the Warm Springs Creek and also the Silver Bow Creek are successfully kept away from the Clark Fork River. Consequently, the river and the tributaries are considered as popular destinations in the country in terms of fly fishing.

The River is home to huge brown trout as well as rainbow trout. There are many fly fishing spots that can be found along the river and trout can be found through its entire length. A wise angler will tend to ignore some slow areas and concentrate on better and productive waters.

Clark Fork is a long river which runs for over three hundred miles in the Montana region. Its lower range of sixty miles is covered with a series of reservoirs and dams. The rest of the river has a fish habitat which every fly fisherman would dream of. An angler would come across whitewater, riffles, brushy and grassy banks with both slow and fast currents. The angler would also not be able to miss the changes that take place in the river, right from its origin to its downstream. At its source in the Warm Springs Wildlife Management Area, the river is narrow enough for people to simply jump across. It begins to expand as it flows and gets several feeder streams. When it reaches the Deer Lodge, it looks sizeable. It becomes a large river when it flows into Missoula. It can be called a massive river when it receives the flow of Flathead River by the Plains. It turns into the state’s biggest river.

A first time angler who wants to do fly fishing should consider the kind of river he or she would like to explore. If the angler is comfortable in a small river set up, then it would be wiser not to plan the fishing in the waters below Missoula. But, if the angler wants an experience of creek fishing, then he or she can fish even at the river’s origin. Float fishing would be great anywhere downstream from the Missoula side.

The Clark Fork River provides sufficient variety in fly fishing to take care of any angler’s needs. It offers great fishing spots where people can pull out huge monster rainbow trout as well as brown trout. The fishing pressure is usually light as an extra benefit. With its proximity to other considerable trout rivers, the Clark Fork has a reputation which attracts many an angler. What the anglers like about Clark Fork River is that they can fish, keeping the river to themselves.

We guide Clark Fork fly fishing trips that run most of the year.