Bathymetric Map of Flathead Lake

Flathead Lake is the largest natural lake in Montana and the largest freshwater lake in the western United States. It is the one of the cleanest lakes of its size in the world. Located in the northwest corner of the state, 7 miles south of Kalispell, it is nearly 30 miles (44 km) long, 16 miles (25 km) wide, and covers 197 square miles (510 square km). Formed by the glacial damming of the Flathead River, the lake is bordered on its eastern shore by the Mission Mountains and on the west by the Salish Mountains. Once known as Selish Lake, the lake takes its name from the Salish (Flathead) Indians who live on the Flathead Indian Reservation located at the southern end of the lake. Kerr Dam, near Polson, regulates the lake's water level and provides hydroelectric power and water for irrigation. Bigfork and Somers occupy the north side of the lake and are very popular amount Calgary tourists. Bigfork offers a lareg varities of rresturants, shopping, theatre, boating, and more. Bigfork Bay is one of the strange and irregular shapped bays in the lake. The bay is where the Swan River meets the lake. The lake has an irregular shoreline and several small islands, the largest of which is Wild Horse Island, a state park. Besides the Flathead River, the Swan River is the lake's other major tributary. The lake is inhabited by native bull trout and cutthroat trout, as well lake trout, yellow perch and lake whitefish. Image File history File links Download high resolution version (612x792, 59 KB)Flathead lake Bathymetric Map by Information Services Unit, Montana Fish, Wildlife & Parks, Kalispell, Montana, 2001 File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Image File history File links Download high resolution version (612x792, 59 KB)Flathead lake Bathymetric Map by Information Services Unit, Montana Fish, Wildlife & Parks, Kalispell, Montana, 2001 File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... State nickname: Treasure State Other U.S. States Capital Helena Largest city Billings Governor Brian Schweitzer Official languages English Area 381,156 km² (4th)  - Land 377,295 km²  - Water 3,862 km² (1%) Population (2000)  - Population 926,865 (44th)  - Density 2. ... For the village on the Isle of Wight, see Freshwater, Isle of Wight. ... Kalispell is a city located in Flathead County, Montana. ... Middle Fork, near Essex, Montana Length 240 km Elevation of the source - m Average discharge - m³/s Area watershed - km² Origin British Columbia, Canada Mouth Basin countries Canada, United States The Flathead River starts in southeast British Columbia, Canada, and flows south through northwest Montana to Flathead Lake before draining... Kootenai group near tipis (ca 1900) The Confederated Salish and Kootenai Tribes of the Flathead Reservation are the Bitterroot Salish, Kootenai and Pend dOreilles Tribes. ... The Flathead Indian Reservation is located in western Montana, it is home to the Bitterroot Salish, Kootenai and Pend dOreilles Tribes - also known as the Confederated Salish and Kootenai Tribes of the Flathead Nation (1). ... Kerr Dam is located at River Mile 72 of the Flathead River at the end of Flathead Lake near Polson, Montana. ... Polson is a city located in Lake County, Montana. ... Hydroelectric dam diagram The waters of Llyn Stwlan, the upper reservoir of the Ffestiniog Pumped-Storage Scheme in north Wales, can just be glimpsed on the right. ... Motto: Heart of the new west Area: 712. ... Wild Horse Island is the largest island in Flathead Lake, the largest freshwater lake in Montana. ... Middle Fork, near Essex, Montana Length 240 km Elevation of the source - m Average discharge - m³/s Area watershed - km² Origin British Columbia, Canada Mouth Basin countries Canada, United States The Flathead River starts in southeast British Columbia, Canada, and flows south through northwest Montana to Flathead Lake before draining... Binomial name Salvelinus confluentus Suckley, 1859 The bull trout (Salvelinus confluentus) is a char of the family Salmonidae. ... Binomial name Oncorhynchus clarki (Richardson, 1836) The cutthroat trout (Oncorhynchus clarki) is a species of freshwater fish in the salmon family (family Salmonidae) of order Salmoniformes. ... This article is about the species of fish. ... For the unit of measurement, see pole. ...

Geology

Flathead Lakes lies at the end of a geological feature called the Rocky Mountain Trench. The trench, which formed with the Rocky Mountains roughly 60 million years ago, extends north into the southern Yukon as a straight, steep valley. During the last ice age this trench was filled by an enormous glacier. As the glacier moved southward, it carved out the trench. Present day Polson, Montana marks the southernmost extent of the glacier during the last ice age. Polson is the site of the glacier's end moraine. Rocky Mountain National Park (photo courtesy of NPS) The Rocky Mountains, often called the Rockies, are a broad mountain range in western North America. ... Motto: none Other Canadian provinces and territories Capital Whitehorse Largest city Whitehorse Commissioner Jack Cable Premier Dennis Fentie (Yukon Party) Area 482,443 km² (9th)  - Land 474,391 km²  - Water 8,052 km² (1. ... Polson is a city located in Lake County, Montana. ...

The large size of the Polson Moraine indicates that the glacier stalled here for several years before retreating. As the climate warmed, a portion of the glacier in the Mission Valley receded more slowly than the main body, which kept the lake basin from being filled with sediment. Eventually this ice also melted, forming a lake behind the moraine. Once the water reached the top of this moraine dam, it began to cut a channel through it. Most moraine dammed lakes drain quickly because water cuts entirely through the moraine. However, Flathead Lake remains because a bedrock hill buried underneath the Polson Moraine prevented the moraine from being completely cut through so the meltwater never completely drained. A moraine dammed lake occurs when a terminal moraine has prevented some meltwater from leaving the valley. ... A moraine dammed lake occurs when a terminal moraine has prevented some meltwater from leaving the valley. ...

Statistics

References

Alt, David. "The Making of Flathead Lake" in Profiles of Montana Geology: A layman's guide to the Treasure State. Butte, MT: Montana Bureau of Mines and Geology, 1984

Flathead Lake Biological Station. "About Flathead Lake." Available at http://www.umt.edu/biology/flbs/aboutflbs/flatheadlake.htm

External Links

Flathead Lake Biological Station
Flathead Lakers
The Flathead from the Space Shuttle by James Conner