Snakes of Madison, WI

Madison snake

Welcome to! I am David, a snake enthusiast living in Madison, WI. Many people don't know that Madison is in fact full of snakes! You just need to know where to find them - they can often be shy and elusive. Some Wisconsin snake species are more common outside of the city limits, in different parts of Dane County WI, but many types of snakes are indeed common in the more urban parts of Madison. This guide is meant to help educate you about the beautiful snakes of Madison, and to help you identify the most common snakes of Madison, as well as the venomous snakes of Madison that you should learn to recognize and avoid. If you want more detail, click here for my complete list of ALL snake species in Madison. Remember the following:

  • Most snakes of Madison are harmless and don't want to encounter you
  • Venomous snakes exist but are uncommon in Madison, Wisconsin
  • Snakes eat rats and mice and are a valuable part of the Wisconsin ecosystem
  • Never kill a snake - if you leave a snake alone, it will leave you alone.

Common Snake Species in Madison

Madison snake Common Watersnake: Also sometimes referred to as the banded watersnake, or by its scientific name Nerodia sipedon, the common watersnake is a fairly long (4 feet/130 cm) serpent that tends to live in watery areas, such as lakes and ponds. It’s non-aggressive and not dangerous to humans, but resembles the venomous cottonmouth, which leads to a lot of unnecessary killings. The common watersnake’s body is colored a dark, reddish-brown or gray, with darker crossbands and blotches on the body and neck. Like with the cottonmouth, the common watersnake tends to grow progressively darker with age. It’s diet consists mainly of fish.

Madison snake Eastern Foxsnake: The eastern foxsnake (Pantherophis gloydi) is a type of rat snake that is non-venomous and fairly common in the Great Lakes region of the US. It usually can be found around marshes and wetlands and is characterized by its tan, grayish base, which contrasts with the dark, squarish blotches on its back. The eastern foxsnake’s diet consists mainly of small mammals and birds. It is currently considered threatened, because of the systematic destruction of its habitat.

Madison snake Common Garter Snake: The common garter snake - the Thamnophis sirtalis - is a type of snake that mainly dwells in forested areas, as well as fields and prairies. It’s a remarkably thin snake, which makes it seem even longer (the adult usually averages around 4 feet or 1.2 meters). It has a pretty varied range of colors, from green to blue to gold, and its body is marked by colorful stripes. While it’s generally not referred to as venomous, since its mild neurotoxic venom cannot affect humans, the common garter snake can be somewhat harmful to small mammals and amphibians, which it feeds on.

Madison snake Milksnake: Similar to the common garter snake, the milksnake is a serpent that is not venomous or dangerous to humans but can use a very mild venom on other animals. It is a subtype of kingsnake, easily distinguishable by its red, black and yellow or white, black, red color patterns (although these can vary widely). It’s a fairly small type of snake, only reaching 24 inches (or 60 cm) in length. Its diet consists mainly of rodents, birds, and other fairly small creatures. The milksnake prefers the night to the day and spends most of its time in forested regions.

Venomous Snake Species in Madison

Madison snake The Timber Rattler: The timber rattler also referred to as the timber rattlesnake or academically, the Crotalus horridus, is the only rattlesnake in the northeast of the US. It grows up to 60 inches in length (150 cm) and is easily noticeable because of its zig-zag cross banding pattern. Usually, the base color is a lighter brown or gray, while the crossbands are mostly dark brown. The timber rattlesnake is usually found in forest areas. It’s considered one of America’s most dangerous snakes because of its long fangs and impressive venom, as well as the fairly dangerous venom. However, few fatalities have been noted, given that the timber rattler is fairly peaceful.

Madison snake The Massasauga: The massasauga (Sistrurus catenatus) is yet another type of rattlesnake (as such, it is also of the pit viper family). The adults aren’t overly large, usually only measuring up to 30 inches (or around 75 cm). Its base color is usually a grayish tan with darker brown or even black blotches on its back. On its sides, the massasauga has rows of alternating dots. While the massasauga’s venom is dangerous and cytotoxic (meaning it destroys tissue), the snake itself isn’t considered aggressive and bites usually occur after deliberate handling. It generally won’t strike unprovoked.

If you're unsure, you can email me a photo of the snake at and I will email you back with the snake's species. If you found a snake skin, read my Found a Skin? page, and you can email me a photo of the skin, and I'll identify the snake for you. If you need professional Madison snake removal help, click my Get Help page, or see the below website sponsor I found, who provides that service.

Remember, the term is not poisonous snakes of Madison, it's venomous snakes of Madison. Poison is generally something you eat, and venom is injected into you. That said, dangerous snakes are very rare in Madison. The few venomous snakes of Dane County are rarely seen. But they are commonly misidentified, so learn about all the snake species of Madison in order to correctly identify them. These snakes are usually also found in the surrounding towns of Dane, Sun Prairie, Middleton, Verona, Stoughton, Waunakee, Fitchburg, Oregon, Mount Horeb, DeForest, Monona, Cottage Grove, Cross Plains, McFarland, Mazomanie, Black Earth, Blue Mounds, Shorewood Hills, Deerfield, Maple Bluff, Marshall, Burke, Roxbury, Albion, Rockdale, Montrose, Primrose, Vermont, Rutland, Dunkirk, and the surrounding areas.

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