‘Snake Road’ Shut Downs as Thousands of Slippery Snakes Are Set to Cross

Red-Sided Garter Snake Mating Ball - Narcisse, Manitoba: Large numbers of male Red-sided Garter Snakes gather around one female.
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Written by Kirstin Harrington

Published: September 5, 2023

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In the state of Illinois, road closures can happen for a variety of reasons. Sometimes a blizzard makes a road impassable, while other times it can simply be construction. But what if we told you that every year, a hoard of slippery snakes makes the state shut down a long stretch of road?

One​​ of these roads is Forest Road 345 in southern Illinois. In order to facilitate a snake migration, the byway that passes through the Shawnee National Forest closes every year as summer comes to a close. 

In order to safeguard the migratory patterns of over 24 species of snakes, authorities block traffic on a 2.7-mile section of this road twice each year. The sole location in the United States where people can witness such a migration takes place in this woodland area.

rock formations along the creek in the Bell Smith Springs area of the Shawnee National Forest in southern Illinois.

Over 500 wildlife species call Shawnee National Forest home.

The state closes down the road from the beginning of September through October. The other time it happens is from March to May. The forest authority emphasizes to observers that it is forbidden to capture, acquire, or harass any species of wildlife. 

Many species that are making their way down Snake Road are venomous. This includes the Northern Cottonmouth, Copperhead, and Timber Rattlesnake species. The forest service also cautions hikers about possible encounters with snakes that are dangerous. 

What is Snake Migration?

The snakes migrate from their burrows to the wetlands in the spring, and in autumn they go in the opposite direction. These slippery snakes must move between their two extremely different habitat types, the lowland lowlands where they forage, and the rocky bluffs where they hibernate. 

Eastern massasauga, Sistrurus catenatus tergeminus, a minor representative of the rattlesnake

The average adult Massasauga is about two feet long.

This circumstance is relatively typical because roads are frequently constructed at the foot of cliffs. According to herpetologists, the earth’s underground temperature is the primary cause of the seasonal movement.

Before 1972, this road could be used for vehicles all year long. As a result, numerous slippery snakes that were traversing the road were killed. The snake road is open to visitors who wish to access this region of the Shawnee National Forest for the purpose of pleasure or scientific research.

Venomous Snakes in Illinois 

Snakes with venom use it to kill prey like birds and smaller creatures. People may experience tissue or nerve injuries from snake venom, but with the right medical care, a snake bite is typically not lethal.

Just four venomous snake species are indigenous to Illinois. The Massasauga is considered endangered by the state. State-listed as threatened is the timber rattlesnake. Only southern Illinois is home to the cottonmouth, while the southern portion of the state is home to copperheads.

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About the Author

Kirstin is a writer at A-Z Animals primarily covering animals, news topics, fun places, and helpful tips. Kirstin has been writing on a variety of topics for over five years. She has her real estate license, along with an associates degree in another field. A resident of Minnesota, Kirstin treats her two cats (Spook and Finlay) like the children they are. She never misses an opportunity to explore a thrift store with a coffee in hand, especially if it’s a cold autumn day!

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