Snakes in Iowa

Iowa has about 30+ species of snakes, and only 4 of them are venomous. The large majority are harmless and beneficial, hunting the rodents and insects that thrive in a state dominated by farmland. Snakes here tend to keep to field edges, prairies, river corridors, and the rocky bluff country, and most slip away long before you get close.

Iowa's landscape is largely converted prairie and cropland, but pockets of original habitat remain. Tallgrass prairie remnants, oak savannas, and sandy terraces hold prairie-adapted snakes, while the Mississippi and Missouri river valleys, along with the rugged Driftless bluffs of the northeast and the Loess Hills of the west, concentrate the most species. Wetlands and oxbows along the big rivers add water-loving snakes to the mix.

Iowa's 4 venomous species split between hills and wetlands. The Timber Rattlesnake lives on the rocky, wooded bluffs of eastern and southern Iowa. The Prairie Rattlesnake just reaches the dry hills of the far western edge along the Missouri River. The Eastern Massasauga and the Western Massasauga are small, secretive wetland rattlesnakes of marshes and wet prairie; both have declined badly and are protected. All four are uncommon, reclusive, and avoid people.

Most snakes Iowans see are harmless. Common garter snakes are everywhere, bullsnakes (gophersnakes) on the prairies hiss and rattle their tails to mimic a rattlesnake and are killed needlessly despite being top-tier rodent hunters, and fox snakes and watersnakes patrol farm ponds and rivers where they are mistaken for something dangerous. Plains hognose snakes put on a hissing, flattening bluff but pose no threat. Bites are uncommon and rarely fatal thanks to antivenom, and most happen when people try to handle or kill a snake. Never assume a wild snake is safe to handle, and if a bite happens, call Poison Control at 1-800-222-1222 or 911.