Musquacook Stream is a tributary to the

Allagash River The Allagash River is a tributary of the Saint John River, approximately long,U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map, accessed June 22, 2011 in northern Maine in the United States. It d ...

in the

North Maine Woods The North Maine Woods is the northern geographic area of the state of Maine in the United States. The thinly populated region is overseen by a combination of private individual and private industrial owners and state government agencies, and is di ...

. The stream originates in a chain of lakes in

Maine Maine () is a state in the New England and Northeastern regions of the United States. It borders New Hampshire to the west, the Gulf of Maine to the southeast, and the Canadian provinces of New Brunswick and Quebec to the northeast and north ...

range 11 townships 10, 11 and 12. The flow sequence is from Clear Lake through Fifth Musquacook Lake into Fourth Musquacook Lake in

Piscataquis County Piscataquis County is a county located in the U.S. state of Maine. As of the 2020 census, its population was 16,800, making it Maine's least-populous county. Its county seat is Dover-Foxcroft. The county was incorporated on March 23, 1838, ta ...

; and from Fourth Musquacook Lake through Third Musquacook Lake, Second Musquacook Lake, and First Musquacook Lake into the Allagash River Musquacook Deadwater in

Aroostook County Aroostook County ( ; french: Comté d'Aroostook) is a county in the U.S. state of Maine along the Canada–U.S. border. As of the 2020 census, the population was 67,105. Its county seat is Houlton, with offices in Caribou and Fort Kent. Kn ...

First Musquacook Lake

First Musquacook Lake is connected to Second Musquacook Lake by a short, broad thoroughfare which keeps both lakes at the same elevation. The first lake extends north from the thoroughfare to overflow into Musquacook Stream upstream of Horse Race Rapids. Searway Brook enters the east shore of the first lake. Summer dissolved

oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as wel ...

concentrations are marginal below the

thermocline A thermocline (also known as the thermal layer or the metalimnion in lakes) is a thin but distinct layer in a large body of fluid (e.g. water, as in an ocean or lake; or air, e.g. an atmosphere) in which temperature changes more drastically with ...

, but

lake trout The lake trout (''Salvelinus namaycush'') is a freshwater char living mainly in lakes in northern North America. Other names for it include mackinaw, namaycush, lake char (or charr), touladi, togue, and grey trout. In Lake Superior, it can also ...

and

brook trout The brook trout (''Salvelinus fontinalis'') is a species of freshwater fish in the char genus ''Salvelinus'' of the salmon family Salmonidae. It is native to Eastern North America in the United States and Canada, but has been introduced elsewhere ...

reach the first lake through the thoroughfare during cool weather.

Second Musquacook Lake

Second Musquacook Lake is the largest of the chain, and supports populations of lake trout and brook trout. Drainage from the third lake enters from the south while Squirrel Brook carries drainage from Squirrel Pond into the east end of the second lake, and Conner Brook and Hesse Brook enter the north end of the lake east of the thoroughfare which overflows to the first lake.

Third Musquacook Lake

Third Musquacook Lake is the smallest of the chain. The third lake supports populations of lake trout and brook trout despite dissolved oxygen deficiencies below the late summer thermocline. Drainage from the fourth lake enters the west end of the Third Musquacook Lake from the south; and the northwest corner of the third lake overflows into the second lake to the north. Drainage from Long Pond enters the east end of the third lake, and Halfway Brook discharges into Musquacook Stream halfway between the second and third lakes.

Fourth Musquacook Lake

Drainage from the fifth lake enters the east end of Fourth Musquacook Lake; and the northwest end of the fourth lake overflows into the third lake to the north.

Hornpout The brown bullhead (''Ameiurus nebulosus'') is a fish of the family Ictaluridae that is widely distributed in North America. It is a species of bullhead catfish and is similar to the black bullhead (''Ameiurus melas'') and yellow bullhead (''A ...

and

fallfish The fallfish (''Semotilus corporalis'') is a North American freshwater fish, a chub in the family Cyprinidae. The fallfish is the largest minnow species native to Eastern North America. Description Average specimens generally measure about in ...

thrive in the fourth lake, and brook trout find refuge from warm summer temperatures where cool springs emerge into the lake.

Fifth Musquacook Lake

Fifth Musquacook Lake is the shallowest of the chain.

White sucker The white sucker (''Catostomus commersonii)'' is a species of freshwater cypriniform fish inhabiting the upper Midwest and Northeast in North America, but it is also found as far south as Georgia and as far west as New Mexico. The fish is commonl ...

thrive in the lake. Clear Lake drains into the south end of the 5th lake, and the north end of the 5th lake overflows into the 4th lake to the west.

Clear Lake

Clear Lake is the deepest lake of the chain and provides good habitat for lake trout, brook trout, and

lake whitefish The lake whitefish (''Coregonus clupeaformis'') is a species of freshwater whitefish from North America. Lake whitefish are found throughout much of Canada and parts of the northern United States, including all of the Great Lakes. The lake white ...

. The north end of Clear Lake overflows into Fifth Musquacook Lake to the north.

Sources

{{Rivers of Maine Allagash River Rivers of Aroostook County, Maine Rivers of Piscataquis County, Maine North Maine Woods