Clark Fork River

The Clark Fork is a river in Montana and Idaho, approximately 360 miles long. The largest river by volume in Montana, it drains an extensive region of the Rocky Mountains in western Montana and northern Idaho in the watershed of the Columbia River, flowing northwest through a long mountain valley and emptying into Lake Pend Oreille in northern Idaho. The Pend Oreille River, which drains the lake to the Columbia, is sometimes included as part of the Clark Fork, giving it a total length of 479 mi, with a drainage area of 25,820 sq mi. In its upper 20 mi in Montana near Butte, it is known as Silver Bow Creek. Interstate 90 follows much of the upper course of the river from Butte to northwest of Missoula.

The Clark Fork should not be confused with the Clarks Fork of the Yellowstone River, which is located in Montana and Wyoming.

It rises as Silver Bow Creek in southwestern Montana, less than 5 mi from the continental divide near downtown Butte, from the confluence of Basin and Blacktail creeks. It flows northwest and north through a valley in the mountains, passing east of Anaconda, where it changes its name to the Clark Fork, then northwest to Deer Lodge. From Deer Lodge it flows generally northwest across western Montana, passing south of the Garnet Range toward Missoula. Five miles east of Missoula, the river receives the Blackfoot River. The confluence is currently drowned by the reservoir behind the nearly 100-year-old Milltown Dam. The dam is slated for removal in 2007.

Northwest of Missoula, the river continues through a long valley along the northeast flank of the Bitterroot Range, through the Lolo National Forest. It receives the Bitterroot River from the south-southwest approximately 5 1/2 mi west of downtown Missoula, and receives the Flathead River from the north near Paradise. It receives the Thompson River from the west near Thompson Falls in southern Sanders County.

At Noxon, Montana, along the north end of the Bitterroots near the Idaho border, the river is impounded by the Noxon Rapids Dam to form a 20 mi long reservoir. It crosses into western Bonner County in northern Idaho near the town of Cabinet, Idaho. Approximately 5 mi west of the Idaho-Montana state line, the river enters the eastern end of Lake Pend Oreille, near the town of Clark Fork.


During the last ice age, from approximately 20,000 years ago, the Clark Fork Valley lay along the southern edge of the Cordilleran ice sheet covering western North America. The encroachment of the ice sheet formed an ice dam on the river, creating Glacial Lake Missoula which stretched through the Clark Fork Valley across central Montana. The periodic rupturing and rebuilding of the ice dam released the Missoula Floods, a series of catastrophic floods down the Clark Fork and Pend Oreille into the Columbia which sculptured many of the geographic features of eastern Washington and the Willamette Valley of Oregon.

In the 19th century the Clark Fork Valley was inhabited by the Flathead tribe of Native Americans. It was explored by Meriwether Lewis of the Lewis and Clark Expedition during the 1806 return trip from the Pacific. The river is named for William Clark. A middle segment of the river in Montana was formerly known as the Missoula River.

Since the late 19th century many areas in the watershed of the river have been extensively mined for minerals, resulting in an ongoing stream pollution problem. Most pollution has come from the copper mines in Butte and the smelter in Anaconda. Many of the most polluted areas have been designated as Superfund sites. Nevertheless the river and its tributaries are among the most popular destinations for fly fishing in the United States.

Today, the Clark Fork watershed encompasses the largest Superfund site in America. As a mega-site, it includes three major sites: Butte, Anaconda, and Milltown Dam/Clark Fork River. Each of these major sites is split up into numerouse sub-sites known as Operable Units.

Coeur d’Alene River

The Coeur d’Alene River flows from the Silver Valley into Lake Coeur d’Alene in Idaho. The stream continues out of Lake Coeur d’Alene as the Spokane River.

Due to mine tailings from the Silver Valley, the river historically had very high levels of lead. Today, however, it is a popular destination for water-skiing, tubing, and swimming for locals.

All of the real bodies of water in the film Dante’s Peak were either the Coeur d’Alene River or one of its tributaries, as Wallace, Idaho, where the movie was filmed, is in the Silver Valley.

Kootenai River

The Kootenay River (spelled Kootenai River for its American portions) is the uppermost major tributary of the Columbia River, flowing through British Columbia, Montana and Idaho. It is one of the few rivers in North America which begins in Canada, enters the United States and then reenters Canada.


The Kootenay originates in the Rocky Mountains of eastern British Columbia, and initially flows south through Kootenay National Park, merging into the Rocky Mountain Trench near Canal Flats, British Columbia (here it passes within a kilometer of Columbia Lake, the headwaters of the Columbia). It continues southwards along the Trench towards the United States border, and at Wardner, British Columbia, it widens into the Lake Koocanusa reservoir created by the Libby Dam near Libby, Montana. Koocanausa spans the Canada-U.S. border; below the dam the river resumes (using the Kootenai spelling), veers westwards out of the Rocky Mountain Trench, collects the tributary Fisher River, Yaak River, and Moyie River, crosses into Idaho, passes through Bonners Ferry, then turns northwards again. It re-enters Canada south of Creston, British Columbia, and widens into Kootenay Lake. At Nelson, British Columbia the Kootenay becomes a river again, now flowing southwest towards Castlegar, where it joins the Columbia River.


In the 1970s, it was proposed that the Kootenay River be diverted into the Columbia River (the two rivers are separated by a distance of no more than one mile in the Rocky Mountain Trench in southeastern British Columbia). This would allow for the generation of increased hydroelectric power. The proposal was strongly opposed by both environmentalists as well as local residents. The economy of southeastern British Columbia is strongly dependent on tourism, with the Columbia River, including Columbia Lake and Windermere Lake (British Columbia), being very popular for summer swimming and boating activities. Diversion of the glacier-fed Kootenay River would have resulted in the Columbia River becoming much deeper and colder, flooding lake-side residences and damaging tourism. As a result, this proposed river diversion was never undertaken.

Kootenai River Drainage

The Kootenai River is located at the north end of the Idaho Panhandle in Boundary County. It originates in southeastern British Columbia, flows south and west through Montana, and northwest through Idaho, then returns to Canada where it flows through Kootenay Lake and joins the Columbia River at Castlegar, British Columbia. At the International border at Porthill, Idaho, it drains approximately 13,700 square miles with an average discharge of 16,100 cfs. The 66 miles of river in Idaho can be divided into two reaches. The 47-mile section from Porthill to Bonners Ferry is a slow moving, broad, meandering river with holes up to 100 feet deep. Water level is affected by a dam at the outlet of Kootenay Lake. The 19 miles of river upstream from Bonners Ferry to Montana flows in a canyon with an average gradient of 3 feet/mile.

The Kootenai River is the only drainage in the State of Idaho where ling (burbot) are native. The Kootenai River is also home to the white sturgeon. Fisheries for both of these species have been closed in response to major declines in these populations. The Kootenai River white sturgeon was listed as an Endangered Species on September 7, 1994.

Inland (redband) rainbow trout are native to the Kootenai River drainage and are present in the mainstem Kootenai River and above barriers in some tributaries. Hatchery rainbow trout have been widely introduced throughout the drainage, however. Other native salmonids include westslope cutthroat trout, bull trout, and mountain whitefish. Introduced eastern brook trout are present throughout the drainage, and a few remnant early spawning kokanee salmon from Kootenay Lake, British Columbia, are present in the mainstem Kootenai River and some west side tributaries during the summer and fall. Kokanee salmon also enter the Kootenai River from Libby Reservoir during some years.

Numerous mountain lakes in the Selkirk and Purcell ranges are stocked with trout fry on a rotating basis. Westslope cutthroat trout, domestic Kamloops rainbow trout, and brook trout are present in most of the lakes, although a few lakes are reserved for specialty species, such as Arctic grayling and golden trout.

Numerous natural lowland lakes provide a mixed bag fishery for trout and spiny-rayed species. Naturalized populations of largemouth bass, black crappie, brown bullhead, yellow perch, and pumpkinseed are present in most lakes. Channel catfish, tiger muskie, and bluegill have been introduced in some lakes. Put-and-take rainbow trout, brook trout fingerlings, and some kokanee salmon are stocked in these lakes to provide salmonid fisheries.

The majority of waters in the Kootenai drainage produce fishing for trout. The Kootenai River and its tributaries, mountain lakes, lowland lakes, and the Moyie River with its tributaries all provide moderate amounts of relatively high quality trout fishing.

Moyie River

The Moyie River is a tributary of the Kootenay River (spelled Kootenai in the United States) in Idaho and the Canadian province of British Columbia. The Moyie River is part of the Columbia River basin, being a tributary of the Kootenay River, which is tributary to the Columbia River.


The Moyie River originates in southeast British Columbia. It flows northeast and east, collecting many headwater streams, before turning south and entering Moyie Lake. The river exits Moyie Lake to the south, flowing south and west by the village of Yahk, British Columbia and Yahk Provincial Park before entering Idaho at Kingsgate, British Columbia and Eastport, Idaho.

In Idaho, the Moyie River flows nearly due south, emptying into the Kootenai River near Moyie Springs, Idaho, several miles east of Bonners Ferry, Idaho. Near its mouth, the Moyie River tumbles over Moyie Falls. Near the falls is Moyie Dam, constructed in 1949.

The river has several oddly named pairs of tributaries. South of Moyie Lake the river collects the tributaries of Sunrise Creek and then Sundown Creek. Farther south, it collects Irishman Creek and then Englishman Creek. At Yahk, Hawkins Creek joins the Moyie River. Hawkins Creek has two tributaries that begin in the United States and flow north into Canada: Canuck Creek and America Creek. Another odd name occurring along the river is the town of Good Grief, Idaho.

The river is paralleled by Highway 95 and the Crowsnest Highway in British Columbia, and, briefly, U.S. Route 95 in Idaho. The river is also paralleled by railroads: the Union Pacific in Idaho and the Canadian Pacific in British Columbia.

In Idaho, the Moyie River and its tributaries lie almost entirely within Kaniksu National Forest.

Natural History

Moyie Falls, near the mouth of the river, effectively blocks the migration of fish. In addition, various dams on the Kootenay River block fish migration. There are resident Kokanee salmon in the upper Moyie River and in Moyie Lake. These are thought to have been introduced during the 1940s and since naturalized.


According to British Columbia’s Geographical Names Information System, the word “Moyie” is a corruption of the French “mouiller” or “mouillé”, a name given by fur trappers referring to the wet conditions, also described by David Thompson in 1808. Thompson called the river “McDonald’s River”. Governor Simpson called it “Grand Quête River”. Captain Palliser called it “Choe-coos River”. The name “Moyie” was originally pronounced “moo-YAY”, indicating its French origin, but today is commonly pronounced “moy-EE”.

Pack River

The Pack River is located in Northern Idaho. Headwaters originate in the Selkirk Mountains, and flow in a southerly direction over 40 miles to the river’s mouth at the northern tip of Lake Pend Oreille. It is the second largest tributary to the lake, after the Clark Fork River.

The Pack River basin drains approximately 185,600 acres. Watershed elevation ranges from a high of 7,550 ft to a low point of 2,050 ft at the lake, with a basin-wide average elevation of 3,730 ft. The upper portion of the watershed is mostly forested, and managed by the U.S. Forest Service. The lower watershed is under mixed public and private ownership, and supports a variety of uses.

Mean annual precipitation in the basin is 35.8 inches, much of which falls as winter snow in the mountains. Mean annual river flow at a mid-river gage is 344 ft³/s, with the highest mean monthly flows occurring in May (939 ft³/s) and the lowest mean monthly flow in September (54.7 ft³/s). Peak river flows for a 100-year event exceed 4,150 ft³/s. Pack River and its tributaries often experience more than one run-off event per year. Mid-winter rain-on-snow events can result in rapid snow melt, and in some years the peak flow from tributary watersheds occurs during these events. Following the 56,000 acres Sundance wildfire in 1967, removal of the forest canopy was hypothesized to have produced an increase in annual stream flow from the basin and an advance of the peak flows by virtue of decreased transpiration losses and earlier snowmelt runoff generation.

Underlying geology in the Pack River watershed is largely granitic, which decomposes into fine particles. Glaciation in the Pack River valley formed ice dams upstream of the confluence of many tributaries, resulting in large deposits of glacial till. Fine sandy sediments deposited in the dammed water are known as glacial fluvial deposits. These sandy areas today appear on mountain side slopes, forming very erosive soils.

Because of the high potential for sediment delivery to the Pack River, land use practices such as road building, timber harvesting, grazing, agriculture, and residential development must be carefully managed. Any loss of riparian vegetation and associated root masses can result in delivery of fine sediment to the stream channel.

The Pack River watershed is home to a number of species protected by the Endangered Species Act. Bull trout, a threatened species, hatch in the upper river, and migrate the length of the river to grow upwards of 30 inches in Lake Pend Oreille before returning as adults to spawn again in the upper river. Terrestrial species found here include the endangered woodland caribou and grey wolf, and threatened species grizzly bear, Canada lynx, and bald eagle. Idaho wildlife species of special concern supported by the Pack River watershed include the wolverine, fisher, northern goshawk, and the white-winged crossbill.

Other relatively abundant wildlife species that rely on this watershed include westslope cutthroat trout, brook trout, kokanee salmon, white-tailed deer, mule deer, moose, elk, black bear, mountain lion, mountain goat, river otter, mink, muskrat, beaver, osprey, peregrine falcon, turtles, a variety of hawks and owls, migratory songbirds and waterfowl, several species of game birds, and many other wetland species.

Near the mouth of the river is the Pack River Flats Wildlife Management Area managed by the Idaho Department of Fish and Game, located 9 miles east-northeast of the town of Sandpoint and 4 miles northwest of the town of Hope. The Pack River Flats is home to a wide variety of wildlife. Canada geese nest on the platforms in the marsh. Geese, swans, and ducks congregate here in spring and fall during their migration. This area also provides public access to wildlife viewing, hunting, and fishing. The Pack River Flats is important ecologically to moose, deer, elk, and waterfowl. Although there is currently no active eagle nesting here, eagles come to the area in the winter to feed on carrion and waterfowl. Before completion of Albeni Falls Dam on the Pend Orille River in 1952, the lake level dropped after the spring runoff. Pack River Flats was a natural meadow then, and archaeological evidence suggests that it was historically an important site for Native Americans.

The Pack River supports numerous recreational pursuits. Fishing, kayaking, canoeing, and river floating are common activities. To protect the river environment and reduce conflicts with other recreationists, motorized watercraft are prohibited above the Highway 200 bridge. In the watershed, hiking, hunting, snowmobiling, rock climbing, and wildlife viewing opportunities abound.

Pend Oreille River

The Pend Oreille River is a tributary of the Columbia River, approximately 130 miles long, in northern Idaho and northeastern Washington in the United States, as well as southeastern British Columbia in Canada. In its passage through British Columbia its name is spelled Pend d’Oreille River. It drains a scenic area of the Rocky Mountains along the U.S.-Canada border on the east side of the Columbia. The river is sometimes defined as the lower part of the Clark Fork, which rises in western Montana. The river drains an area of approximately 25,820 sq mi, mostly through the Clark Fork and its tributaries in western Montana.


The Pend Oreille River begins at Lake Pend Oreille in Bonner County, Idaho in the Idaho Panhandle, draining the lake from its western end near Sandpoint (The Clark Fork River enters the lake from is eastern end). It flows west, receiving the Priest River from the north at the town of Priest River, then flows into southern Pend Oreille County in northeastern Washington at Newport. Once in Washington it turns north, flowing along the eastern side of the Selkirk Mountains. It flows roughly parallel to the Idaho border for approximately 50 mi, through the Colville National Forest, past Tiger and Metaline Falls. It crosses the international border into southeastern British Columbia, looping west for about 15 miles and joining the Columbia from the east, approximately 2 mi north of the international border and approximately 5 miles south of Montrose.


There are five dams on the Pend Oreille River: Waneta (owned by Teck Cominco) and Seven Mile (B.C. Hydro) dams in Canada, Boundary (Seattle City Light), Box Canyon (Pend Oreille County PUD), and Albeni Falls (U.S. Army Corps of Engineers) dams in the United States. None provide for fish passage.

Pend Oreille River Drainage

The Pend Oreille River drains about 24,200 square miles of land in western Montana and the Panhandle of northern Idaho. Most of the 2,133 square miles of the drainage within Idaho lie in Bonner County. Major tributaries of the Pend Oreille River include the Clark Fork, Flathead, Bitterroot, Blackfoot, and St. Regis rivers in Montana and the Priest and Pack rivers and Lightning Creek in Idaho.

Pend Oreille Lake is the largest natural lake in Idaho covering 85,960 surface acres with a shoreline length of 111 miles. The lake basin is deep and steep-sided with a maximum depth of 1,152 feet and mean depth of 538 feet. The combined surface area of Pend Oreille Lake and the backwaters of Albeni Falls Dam, located on the Pend Oreille River 23 miles downstream of the lake, is 94,720 acres.

Priest and Upper Priest lakes are glacial lakes connected by a shallow winding channel. Priest Lake has a surface area of about 23,360 acres with a maximum depth of 369 feet and mean depth of 123 feet. Upper Priest Lake is accessible only by boat or foot trail, covers about 1,400 surface acres, and has a maximum 100-foot depth. Spirit Lake has a surface area of 1,477 acres and a maximum depth of about 90 feet.

Westslope cutthroat trout, pygmy whitefish, mountain whitefish, and bull trout are the only salmonids native to the Pend Oreille drainage in Idaho.

Introduction of exotics has played both a positive and negative role in shaping the fisheries of the Pend Oreille drainage. Lake Superior whitefish were introduced to Pend Oreille in 1889. Eastern brook trout were widely distributed in the early 1900s and were successful in outcompeting and eventually replacing native cutthroat in some watersheds. Lake trout were introduced into Priest and Pend Oreille lakes in the 1920s.

During the 1930s, kokanee salmon became established in Pend Oreille Lake by moving naturally into the system from Flathead Lake in Montana in the early 1900s. Kokanee salmon were transplanted from Pend Oreille Lake to Spirit Lake in 1937 and Priest Lake in the 1940s. Kokanee established themselves quickly in each of these lake systems, displacing native mountain whitefish in the open water habitat.

The introduction of channel catfish, tiger muskie, and bluegill sunfish has diversified the warmwater fishery in several lakes. Other game fish in the Pend Oreille drainage include brook trout, brown trout, largemouth and smallmouth bass, northern pike, tiger muskie, yellow perch, black crappie, pumpkinseed, bluegill, bullhead, and channel catfish.