The Prairie River is a tributary

Tributary

A tributary or affluent is a stream or river that flows into a main stem river or a lake. A tributary does not flow directly into a sea or ocean...

 of the Wisconsin River

Wisconsin River

-External links:* * * , Wisconsin Historical Society* * * *...

 in north-central Wisconsin

Wisconsin

Wisconsin is a U.S. state located in the north-central United States and is part of the Midwest. It is bordered by Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake Michigan to the east, Michigan to the northeast, and Lake Superior to the north. Wisconsin's capital is...

 in the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

. It is about 40 mi (65 km) long. Via the Wisconsin River, it is part of the Mississippi River

Mississippi River

The Mississippi River is the largest river system in North America. Flowing entirely in the United States, this river rises in western Minnesota and meanders slowly southwards for to the Mississippi River Delta at the Gulf of Mexico. With its many tributaries, the Mississippi's watershed drains...

 watershed

Drainage basin

A drainage basin is an extent or an area of land where surface water from rain and melting snow or ice converges to a single point, usually the exit of the basin, where the waters join another waterbody, such as a river, lake, reservoir, estuary, wetland, sea, or ocean...

.

Course

The Prairie River flows from Horseshoe Lake in northwestern Langlade County

Langlade County, Wisconsin

Langlade County is a county located in the U.S. state of Wisconsin. As of 2000, the population was 20,740. Its county seat is Antigo.-Geography:According to the U.S. Census Bureau, the county has a total area of , of which is land and is water...

 and follows a generally southwestward course through southeastern Lincoln County

Lincoln County, Wisconsin

Lincoln County is a county located in the U.S. state of Wisconsin. As of 2000, the population was 29,641. Its county seat is Merrill.-Geography:According to the U.S...

 to the city of Merrill

Merrill, Wisconsin

Merrill is a city in Lincoln County, Wisconsin, United States. The population was 10,728 at the 2010 census. The city is located to the south of and adjacent to the Town of Merrill....

, where it joins the Wisconsin River.

In an effort to restore trout

Trout

Trout is the name for a number of species of freshwater and saltwater fish belonging to the Salmoninae subfamily of the family Salmonidae. Salmon belong to the same family as trout. Most salmon species spend almost all their lives in salt water...

 habitat, the Wisconsin Department of Natural Resources

Department of Natural Resources

Many sub-national governments have a Department of Natural Resources or similarly named organization:Australia*Queensland Department of Natural Resources and MinesCanada*Natural Resources Canada*New Brunswick**New Brunswick Department of Natural Resources...

 removed two dam

Dam

A dam is a barrier that impounds water or underground streams. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees are used to manage or prevent water flow into specific land regions. Hydropower and pumped-storage hydroelectricity are...

s on the Prairie River in Lincoln County in the 1990s, making the river free-flowing for its entire course.