Snakes in Iowa

Snakes of Iowa

June 23, 2014

There are a lot of animals labeled as pests and some are unfortunately feared and therefore killed. In Iowa, there are 27 different species of snakes. Many of these species are beneficial to the ecosystem and especially helpful to have on farmers' land because of their wide range of diet. And of these 27 snakes, only three present an immediate danger and should be avoided. With the help of Iowa's reptile experts at, we have compiled a list of Iowa snake species. Read on to learn identification, population and feeding habits of Iowa snakes.

Types of Snakes Found in Iowa:

  • Brown Snake: This small Iowa species is only 13 to 18 inches long and has simple markings. They are not venomous and live in all areas of the state except the northwestern part of Iowa. Because they are acclimated to different habitats, you might find them in your backyard, at a park or even in the city.

  • Copperhead: These snakes are secretive and like to take refuge in hidden places, thus making location and population difficult to determine. However, when found, copperhead snakes are commonly seen on rock outcroppings and have only been spotted in a tiny area of southeastern Iowa. Copperhead's do tend to bite, however, their venom is mild and rarely is fatal for humans. 

  • Diamondback Watersnake: This is the largest Iowa water snake and measures 48 to 63 inches. Although its name implies that it might have diamond markings, this snake only has small blotches and bar patterns. So far, the diamondback watersnake has been found in only three counties in southeastern Iowa near the Mississippi River. It is nonvenomous.

  • Eastern Garter Snake: This is one of Iowa's only unprotected snake species because there is an abundant population throughout the state. They are medium sized, measuring 14 to 48 inches and have three longitudinal stripes, the dorsal stripe is usually yellow. The eastern garter snake is likely to bite when handled but is not venomous.

  • Eastern Hognose Snake: This snake might act like a cobra when alarmed, but have no fear, bites are rare and they are not considered venomous. They are 24 to 46 inches long and eat amphibians and small mammals. They range in color from black, to gray, to olive and some have a blotched pattern on their back.

  • Eastern Racer: This snake is easily identifiable by their abnormally blue or greenish color. Their throat and neck are bright yellow and they have no head or dorsal markings. They are the fastest snakes in Iowa, active hunters and live in fields throughout Iowa. When the Eastern racer feels threatened they will rarely bite, instead slither away and go into a burrow. They are not dangerous.

  • Gopher Snake: This snake is more commonly called a bull snake and is Iowa's largest snake species. Their length ranges from 37 to 72 inches and along their back are speckled blotches. They are found statewide in Iowa and live in open prairies and grassy meadows. Although they can appear dangerous because of their hissing, vibrating their tails, and puffing out their bodies, the gopher snake is not venomous.

  • Graham's Crayfish Snake: This snake is 18 to 28 inches long. Like the name implies, Graham's crayfish snake eats mainly crayfish, but they also feed on fish and amphibians. They are not venomous and are not aggressive.

  • Lined Snake: At 8 to 10 inches long, this little snake resembles a garter snake. You can identify it by its white mid dorsal stripe and light colored lateral stripes on each side of the snake. If they were to bite, it would cause no harm to you, your children or your pets. This snake's diet consists of soft-bodied insects, earthworms, slugs and snails. 

  • Massasauga Rattlesnake: This is a small rattlesnake, ranging from 17 to 39 inches and is venomous. You can recognize it by its black spots on grey background. While it used to be found abundantly in eastern Iowa, this snake is endangered and today only a small population is found in marshes, lakes and rivers in eastern Iowa. If you find one of these snakes, DO NOT pick them up because their bite (even a reaction movement hours after death) can be fatal.

  • Milk Snake: These snakes are found statewide and are most often found in rocky hillsides. You can identify a milk snake by its long body (24 to 52 inches), slender build and large blotchy pattern. This snake is not venomous and rarely comes into contact with humans.

  • Northern Water Snake: This is the most common Iowa water snake and is found in all marshes, streams, lakes and ponds in Eastern Iowa. If threatened, this snake will bite repeatedly, release musk and fecal matter. Although they are nonvenomous, this snake's saliva will make lacerations bleed plentifully. To treat the wound, you must apply soap and water. There is no need to visit the doctor because of a bite from any of Iowa's water snakes.

  • Plainbelly Watersnake: Like their name implies, the plainbelly water snake has no markings and can be found in any body of water near the Mississippi River or in the river itself. It is a very rare species and to date has only been located in one Iowa county. This snake is likely to bite, however, they are not venomous.

  • Plains Garter Snake: Similar to other garter snakes, the plains garter snake has three long stripes, the dorsal stripe typically yellow or orange. This is Iowa's most common snake, found in all different environments in all 99 counties. They are nonvenomous and feed on mice, bird eggs, earthworms and small amphibians.

  • Prairie Kingsnake: Living in prairies, fields and woodlands in southern Iowa, these snakes are active from April to October. You might find them roaming about your barn or slithering across a road at sunrise or sunset. But don't pick them up because some will bite. However, the prairie kingsnake is helpful to have around farmland because they eat other snakes, mice and other pests. This snake is nonvenomous.

  • Prairie Rattlesnake: Found only in Plymouth County, this rare Iowa species IS venomous. It is 35 to 45 inches long, has a rattle at the end of its tail, patterned scales and color ranging in different shades of brown.

  • Redbelly Snake: Known as Iowa's smallest snake species, the redbelly snake is only 7 to 10 inches long. During its life, this snake takes on two different colored skins. The first is dark brown with one light mid dorsal stripe and the other is a shade of gray with four black or red stripes running from its head to its tail. This is one species that is typically found in northeastern Iowa in woodlands with a nearby water source. This little snake eats slugs, earthworms and insect larva and is nonvenomous.

  • Ringneck Snake: Like its name indicates, the ringneck snake is identifiable by a yellow or orange ring around its neck. Its belly is orange with small black spots and the underside of its tail is bright red. Although it is small (only 10 to 15 inches long), it is a nonvenomous constricting snake and eats salamanders, frogs, lizards, newborn rodents and even other small snakes. They live in all parts of Iowa except northern counties. If you find one in a woodpile around your home or a bundle of firewood, simply pick them up and carry them back outdoors.

  • Smooth Earth Snake: This small snake measures only 7 to 10 inches and is plain brown in color. They live in secretive areas under rocks or logs in southern Iowa and do not present any danger.

  • Smooth Green Snake: With its bright, emerald green color, you won't mistake the smooth green snake for another species. They are smaller than other snakes at 12 to 22 inches long and live in central Iowa in grassy meadows. You might find one along a bike route or railroad track, sometimes even on your porch if it's brought home by your dog! No worries though, this serpent is nonvenomous and feeds solely on insects and rarely bites.

  • Speckled Kingsnake: At 36 to 48 inches long, the speckled serpent slithers around pairies, open grasslands and streams in southern Iowa. You can recognize it by its shiny black scales and yellow or white speckles. They will bite when handled but are nonvenomous.

  • Timber Rattlesnake: This large venomous Iowa rattlesnake has a diamond shaped head and a relatively thin neck. You can recognize the timber rattlesnake from a black chevron print that runs across its entire back. You'll find them in southern Iowa along the Mississippi River or along rocky road cuts by dense foliage.

  • Western Fox Snake: Measuring 36 to 56 inches, this large-bodied snake eats rodents and birds. They can swim and climb trees very easily, so it is likely that you might find them resting on a tree branch or crossing a river. They are not venomous and are found in 50 counties throughout Iowa.

  • Western Rat Snake: This snake is among Iowa's largest snakes at 40 to 74 inches in length. They are nonvenomous and generally black. They live mainly in forested areas in southern Iowa and along the Mississippi River.

  • Western Ribbon Snake: A type of garter snake, the western ribbon snake is 20 to 30 inches long. Along its back are three orange or cream colored stripes that run from its head to its tail. Unlike other Iowa garter snakes, you'll find this one around all types of water. This snake might bite, but it is not venomous.

  • Western Worm Snake: Found in woodlands and rocky wooded areas, this small, nonvenomous snake lives in the southern part of Iowa. It's seven inches long and ranges in color from blue to purple to black. It's easily recognizable from other Iowa snakes as its back has no markings and its belly is pink.

  • Western Hognose Snake: This is a medium sized snake that ranges from 15 to 39 inches and is very rare as it has lost much of its natural sandy prairie habitat. Nonvenomous and unknown to bite, the western hognose snake's method of defense is to hide its head under its coils. If they are discovered they'll act much like a bull snake, puffing up their body and hissing.

Snake Activity

As temperatures become warmer, snakes begin to move about and come out of their burrows. In Iowa, most snakes are active from mid-April to September and often mate in both the spring and early fall. Because of freezing temperatures, snakes will hibernate below ground and under several layers of rocks to survive the cold Iowa winter.

Where Will I find Snakes?

Iowa's prairies, ponds and forests are ideal living areas for many species of Iowa snakes. However, some might view your yard, agricultural land or pond as a welcome area to roam and hunt. Although most snakes do most of their hunting under the protection of nightfall, you might find one while gardening, mowing the lawn, fishing or playing in a park. Because Iowa has many different species of snakes, it is best to identify a specific species to determine how likely it is your home will have a visitor.