The 5 Most Snake-Infested Rivers in Wisconsin

Sunset, Wisconsin, River, Golden Hour, Commercial Dock
© Michael Jordan/ via Getty Images

Written by Mackenzie Lesher

Published: September 26, 2023

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Nicknamed “America’s Dairyland,” Wisconsin is home to a vibrant dairy production industry, the scenic Great Lakes, and Harley Davidson. With a vibrant aquatic ecosystem, Wisconsin is home to a plethora of snakes that thrive within its many rivers. There are 22 different native species of snakes in Wisconsin, but only 2 are venomous, with both being rattlesnakes. None of Wisconsin’s rivers have native venomous water snakes.

According to the Wisconsin Department of Natural Resources, the state has approximately 12,600 rivers and streams, including the famous Mississippi River. Let’s find out the top five most snake-infested rivers in Wisconsin!

Water Snakes Found in Wisconsin Rivers

Northern Water Snake Wisconsin

Northern watersnakes have a habitat range that spans from North Carolina to southern Quebec.

©Jason Patrick Ross/

Though Wisconsin is not the most snake-populated region in the United States, it still has a large variety of species that live within its borders. Some of these snakes inhabit the rivers within the state, such as water snakes. Other types of snakes will venture into the water, including the venomous timber rattlesnake and the eastern massasauga, though this is less common.

Every species of snake can swim, but only water snakes are classified as semi-aquatic. This means they have adapted to live in water-based habitats and on land over time. About 200 species of snakes are classified as water snakes in the world.

There are six species of water snakes in Wisconsin:

  • Northern watersnake¬†(Nerodia sipedon)
  • Plains garter snake (Thamnophis radix)
  • Common garter snake (Thamnophis sirtalis)
  • Eastern ribbon snake¬†(Thamnophis saurita)
  • Western ribbon snake (Thamnophis proximus)
  • Queen snake (Regina septemvittata)

None of the water snakes in Wisconsin are venomous. The western ribbon snake, eastern ribbon snake, and queen snake are state-endangered species. The plains garter snake is threatened.

No native snake species in Wisconsin, including the two venomous snakes listed, will attack unprovoked.

Some snakes found in Wisconsin are not native to the state, but humans have released them there. Normally, these are former pets that the owners did not want or could not take care of. The Burmese python, and the carpet python, have both been found outside of their natural habitats as a result of human relocation.

Most Snake-Infested Rivers in Wisconsin

With the amount of rivers that cross through Wisconsin, it is no wonder snakes inhabit some of them. Find out the top five most snake-infested rivers in Wisconsin!

1. The Mississippi River

The Mississippi River is the second-largest river in North America.

©dangarneau/ via Getty Images

One of the most famous rivers in America, this river is home to a wide variety of wildlife, including some species of snakes. Some of the species that live in the Mississippi River in Wisconsin are the northern watersnake, the bullsnake, and the timber rattlesnake. Sometimes the rare and endangered eastern massasauga inhabits the nearby riverbanks too. Both timber rattlesnakes and the eastern massasauga are venomous.

2. The Menominee River

The Menominee River forms part of the boundary between the Michigan and Wisconsin border.

©Jamie Casper/ via Getty Images

Stretching 116 miles across both Michigan and Wisconsin, the Menominee River is a natural wonder that is admired across both states. After 30 years of conservation and restoration efforts, the river was recently delisted from a list of the most polluted rivers in the Great Lakes. Because of this, wildlife populations such as the northern pike, osprey, otter, and painted turtle have started to flourish again. With the ecosystem being so vibrant, it is no wonder that some snakes inhabit the river. These snakes include the common garter snake, eastern milksnake, and butler’s garter snake.

3. The Chippewa River

Aerial photograph of the Chippewa River Damn with Lake Wissota in the distance in Chippewa Falls Wisconsin

In the past, the Chippewa River was used as a floatway for paper mills and lumbering.

©Matthew A Reddy/

A hotspot for tourism for kayaking and canoeing, the Chippewa River is a scenic spot to visit. Before visiting, however, people should know that snake sightings are common on this river. The Chippewa is home to snakes such as the eastern massasauga, which is normally found at the mouth of the river. The eastern massasauga is venomous and should be avoided. The eastern massasauga is scared of humans and will only attack if provoked, and it is illegal to kill them because of their endangered status. Another snake that inhabits the Chippewa River is the northern watersnake, which can grow up to 2 to 4 feet long. Other snakes that live in the river are the eastern foxsnake, the common watersnake, the eastern hognose, and the eastern milksnake.

4. The Fox River

The Fox River has undergone massive efforts by environmentalists to clean up the pollution within the river.

©KaraGrubis/ via Getty Images

The principal tributary of Green Bay, the Fox River is an important ecological landmark in Wisconsin. The Fox River unfortunately has been polluted for many years because of its history of being an important industrial site. Efforts have been made to clean the polluted river, but much of the chemical and sewage waste still remains. Despite this, wildlife finds a way to survive. This includes many species of snakes, including the queen snake, northern watersnake, and eastern foxsnake.

5. The Wisconsin River

The Wisconsin River is an important tributary of the Mississippi River.

©baluzek/ via Getty Images

Approximately 430 miles long, the Wisconsin River is the longest river in the state. It is home to beautiful scenery and wildlife that are admired by residents and tourists alike. Some of this wildlife includes snakes such as the common watersnake, ring-necked snake, North American racer, and the timber rattlesnake. The river does have venomous snakes, with the timber rattlesnake being a pit viper which is always venomous.

#RiversSnakes Found
#1The Mississippi RiverThe eastern massasauga, timber rattlesnake, and the bullsnake
#2The Menominee RiverThe common garter snake and eastern milksnake
#3The Chippewa RiverThe eastern foxsnake, eastern hognose, and the eastern massasauga
#4The Fox RiverThe queen snake, northern watersnake, and the eastern foxsnake
#5The Wisconsin RiverNorth American racer, timber rattlesnake, and the common watersnake
A summary of the snakes found in Wisconsin rivers.

Other Animals Found Near Rivers in Wisconsin

The American badger is Wisconsin’s official state animal.

©Photography by Adri/ via Getty Images

The badger is an important symbol to the people of Wisconsin and is their official state animal. Badgers are nocturnal small mammals with long claws to burrow with. They are of least concern in Wisconsin but are still protected under the law against trapping and hunting. They are related to otters, ferrets, and minks.

The river otter is extremely intelligent, often using tools to help crack open mussels and sea urchins.

©Cloudtail_the_Snow_Leopard/ via Getty Images

The river otter is a vital animal in the history of Wisconsin and in the modern day. It was a main draw for fur trappers to come to the state and supplied the Native American population with a resource for thousands of years. They are playful and sociable animals, typically living in groups to ensure better survival chances. Otters are excellent swimmers and eat fish, frogs, and turtles.

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About the Author

I'm an avid animal lover and writer who loves researching new and exciting topics. I grew up soaking up knowledge about animals, nature and the unknown.

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