10 US Lakes, Rivers and Swamps Where You Are Most Likely to See Snakes
Warm, slow water full of fish and frogs is snake heaven. Here is where to expect them, which ones you will see, and why most of them are harmless.
Snakes gather where food is easy and cover is thick. Around water, that means shallow, weedy shorelines, cypress swamps, beaver ponds and rocky banks, mostly in the warmer half of the country. A lake with plenty of frogs, minnows and sunfish, and plenty of logs to bask on, will have plenty of snakes.
The great majority are water snakes of the genus Nerodia. They are thick, dark, strong swimmers that eat fish and frogs, and they have no venom. They do have short tempers when grabbed, and they will bite and smear musk on anyone who picks one up, but left alone they are harmless.
The United States has only one venomous snake that is truly at home in the water: the cottonmouth, or water moccasin. It lives only in the Southeast, from southeastern Virginia to Florida and west to central Texas, and north up the Mississippi valley to southern Illinois. Outside that range, any snake swimming in a lake is not a cottonmouth.
Nobody keeps an official ranking of snake waters. Treat this list as a guide to ten places with a well-earned reputation among anglers, paddlers and biologists, and to what you can expect to see in each.
Read all the way to the end. The last place on the list is where people most often misidentify what they see.
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Florida
1. The Everglades
Have you been here?The Everglades is a slow, shallow river of sawgrass about fifty miles wide, edged with cypress, mangrove and pine. More than two dozen native snake species live in and around Everglades National Park. The ones visitors actually see are Florida banded water snakes, brown water snakes and Florida green water snakes along the boardwalks and canals, with black racers and rat snakes on the drier ground.
AdvertisementFour native species here are venomous: the Florida cottonmouth, the eastern diamondback rattlesnake, the dusky pygmy rattlesnake and the coral snake. Cottonmouths are the ones seen near water, usually coiled at the edge of a trail or canal bank.
The Everglades is also the one place in the country where an introduced snake has truly taken over. Burmese pythons, descended from escaped and released pets, have been breeding in south Florida since at least the 1990s and now number in the tens of thousands. They have been linked to steep declines in raccoons, opossums, marsh rabbits and other mammals. They are not venomous, and despite their numbers they are so well camouflaged that most visitors never see one.
AdvertisementThe dry season, from December through April, is the best time to visit. Water levels fall, wildlife concentrates around the remaining pools, and the mosquitoes ease.
What you will seeBanded and brown water snakes basking beside the Anhinga Trail and Shark Valley canals, and the occasional cottonmouth. Report any python sighting to park staff rather than approaching it. -
Georgia and Florida
2. Okefenokee Swamp
Have you been here?The Okefenokee covers more than 400,000 acres of blackwater swamp, floating peat and cypress forest on the Georgia and Florida line. Most of it is a national wildlife refuge, and it is one of the largest intact freshwater swamps in North America. More than thirty species of snake live there.
AdvertisementPaddlers on the marked canoe trails see banded water snakes most often, stretched along low branches and on the edges of floating peat mats. Brown water snakes hang in the shrubs over the channels. Ribbon snakes, slim and striped, hunt frogs in the lily pads. All three are harmless.
Cottonmouths are common and should be expected along trail edges, on the wooden camping platforms and around the boat basins. The drier pine islands hold eastern diamondback and timber rattlesnakes, though paddlers seldom meet them.
AdvertisementSpring is the prime season. From March through May the snakes bask for much of the day, the alligators are active, and the heat is still bearable.
In a blackwater swamp, the snake you notice is one of many that noticed you first.
What you will seeBanded water snakes on branches and cottonmouths on the banks. Check a camping platform with a light before you step onto it at night.Advertisement -
Louisiana
3. Atchafalaya Basin
Have you been here?The Atchafalaya is the largest river swamp in the United States, close to a million acres of bayous, cypress and tupelo forest, and backwater lakes in south-central Louisiana. The water is warm, shallow and rich in fish, frogs and crawfish, and the snake population reflects it.
The broad-banded water snake is the classic species here, a handsome animal with wide dark bands separated by yellow. Diamondback water snakes, the largest water snakes in the region at up to five feet, bask on logs and brush. Plain-bellied water snakes and Mississippi green water snakes are also common, and the slender Graham's crayfish snake lives up to its name along the bayou banks. None of them is venomous.
AdvertisementCottonmouths are plentiful throughout the basin. They bask on logs, levees and the bases of cypress trees, and they are active on warm nights.
Anglers and crawfishers here work with their hands in the water, around traps, trotlines and stumps, and that is where care is needed. Lift traps and lines with a hook or gaff, and look before you reach.
What you will seeSeveral kinds of water snake on nearly every log in spring, and plenty of cottonmouths. A swamp tour from March through June shows the most.Advertisement -
Ohio
4. Lake Erie islands
Have you been here?The Lake Erie water snake lives nowhere in the world except the limestone islands of western Lake Erie, including South Bass, Middle Bass and North Bass islands and Kelleys Island in Ohio, and Pelee Island in Canada. It is a form of the northern water snake, usually plain gray with faint or no banding, and it is entirely harmless.
By the 1990s, shoreline development and deliberate killing had reduced it to a couple of thousand adults. It was listed as a threatened species under federal law in 1999. Protection of shoreline habitat and a patient public education effort on the islands turned things around, and it was removed from the federal list in 2011, one of the clearest recoveries of any American reptile.
AdvertisementAn unexpected ally helped. The round goby, an invasive fish that spread through Lake Erie in the 1990s, became the snake's main food. The snakes now grow faster and larger than they did before.
The snakes are easy to see from May through September. They bask on shoreline rocks, breakwalls and docks, sometimes in groups, and swim along the shore hunting. They remain protected under Ohio law.
AdvertisementWhat you will seeGray water snakes on rocks and docks around Put-in-Bay and Kelleys Island. There are no venomous snakes on the islands, so simply let them be. -
Tennessee
5. Reelfoot Lake
Have you been here?Reelfoot Lake lies in the northwest corner of Tennessee, close to the Mississippi River. It was formed by the New Madrid earthquakes of 1811 and 1812, which dropped the land and let the river flood a cypress forest. The result is a shallow lake of about 15,000 acres, studded with cypress trees and stumps and edged with lily pads.
AdvertisementIt is superb snake habitat. Diamondback, broad-banded and plain-bellied water snakes are all common, along with the Mississippi green water snake, which is rare elsewhere in Tennessee. They bask on cypress knees, stumps and the limbs of fallen trees.
Cottonmouths are abundant, more so than almost anywhere else in the state. They are seen along the boardwalks at the state park, on the lake's edges, and crossing roads on warm, wet evenings in spring and fall.
Reelfoot is a famous crappie and bluegill lake, and the fish hold tight to the stumps and trees where the snakes rest. Anglers should look over a stump before tying up to it or reaching for a snagged line.
AdvertisementWhat you will seeCottonmouths and water snakes among the cypress knees from April through October. The state park boardwalk gives a safe, close view. -
Texas and Louisiana
6. Caddo Lake
Have you been here?Caddo Lake spreads across the Texas and Louisiana line in a maze of bayous, sloughs and flooded bald cypress hung with Spanish moss. It covers roughly 25,000 acres, much of it only a few feet deep, and it has one of the largest cypress forests in the country.
AdvertisementThe diamondback water snake is the species paddlers notice first. It is big, heavy and marked with a dark chain pattern, and it lies on branches a foot or two above the water. It is harmless but looks formidable, and it is regularly mistaken for a cottonmouth. Broad-banded and plain-bellied water snakes are common too, and western ribbon snakes hunt along the weedy margins.
Cottonmouths live throughout the lake. They tend to sit lower than the water snakes, on logs, root tangles and the muddy bases of cypress trees.
The paddling trails are best in April, May and October. Summer is hot, and floating vegetation can choke the narrower channels.
What you will seeDiamondback water snakes on low branches and cottonmouths at the waterline. Keep your boat away from overhanging limbs and you will not disturb either.Advertisement -
Florida
7. Lake Okeechobee
Have you been here?Lake Okeechobee is the largest lake in Florida and one of the largest wholly within the United States, about 730 square miles of water that averages only nine feet deep. Its western and southern shores are a broad marsh of bulrush, cattail, spikerush and lily pads, and that is where the snakes are.
The Florida banded water snake is the common species, along with the Florida green water snake, which is the largest water snake in North America and lives out in the vegetation rather than on the banks. Brown water snakes bask in the willows along the rim canal and the Kissimmee River.
AdvertisementFlorida cottonmouths live around the entire lake, especially along the canals, the dike and the marsh edges. Burmese pythons have also been found in the region as the population spreads north from the Everglades.
Okeechobee is one of the country's great bass and crappie fisheries. Anglers wading or fishing the grass should watch where they step when launching, and should not lift a fish from thick vegetation by hand without looking first.
AdvertisementWhat you will seeFlorida banded and green water snakes in the marsh, mostly glimpsed as they slide away. Winter and spring offer the best viewing and the best fishing. -
South Carolina
8. Santee Cooper lakes
Have you been here?Lakes Marion and Moultrie, known together as Santee Cooper, were created in the early 1940s when the Santee River was dammed and thousands of acres of swamp forest were flooded. The upper end of Lake Marion is still a standing cypress and tupelo forest, and it is famous for catfish, striped bass and crappie.
It is just as well known for the brown water snake. This large, heavy species has a squared-off head and dark square blotches, and it climbs better than any other American water snake. On sunny days it lies draped over branches as much as twenty feet above the water.
AdvertisementWhen a boat passes underneath, a startled snake lets go and drops. Now and then one lands in the boat, which is the origin of most stories about moccasins attacking anglers. The brown water snake is not venomous. Banded and red-bellied water snakes share the lakes with it.
Cottonmouths are present, mainly in the swampy upper lake and the backwaters, and they stay low on logs and banks.
AdvertisementThe snake that falls into a fishing boat is almost always a harmless one that was trying to get away.
What you will seeBrown water snakes on branches above the water from April through October. If one drops in, ease it out with a paddle or net. Do not grab it. -
Mississippi River
9. Backwaters and oxbows
Have you been here?The main channel of the lower Mississippi is too fast and too cold for most snakes. The life is in the quiet water beside it: the oxbow lakes, sloughs, chutes and flooded timber that line the river from southern Illinois to the Gulf.
AdvertisementThese backwaters warm quickly in spring and fill with shad, sunfish and frogs. Diamondback water snakes are the most conspicuous residents, basking in numbers on brush and riprap. Plain-bellied water snakes, broad-banded water snakes and Mississippi green water snakes are also common, and all are harmless.
Cottonmouths occur along the river from far southern Illinois and Missouri southward, and they become steadily more common through Arkansas, Mississippi and Louisiana. North of that, in Iowa, Wisconsin and Minnesota, the river's snakes are northern water snakes, and none of them is venomous.
High water changes everything. When the river floods in spring, snakes are pushed onto levees, driftwood, boat ramps and sometimes porches, and they are far more visible than usual.
AdvertisementWhat you will seeDiamondback and plain-bellied water snakes on logs and rocks, with cottonmouths in the southern stretches. Be most alert on levees and ramps during and just after a flood. -
Missouri and Arkansas
10. Ozark streams
Have you been here?The Current, Jacks Fork, Eleven Point and Buffalo rivers are clear, cool, spring-fed streams that run over gravel between limestone bluffs. They are some of the most popular floating rivers in the country, and on a summer weekend thousands of people are on the water.
AdvertisementThe snake they see is the northern water snake, a brown, banded animal two to three feet long. It basks on gravel bars, root wads and low branches, and hunts minnows and sculpins in the shallows. It is harmless. When cornered, it flattens its head and body and strikes, which is why so many floaters are sure they have met a cottonmouth.
Cottonmouths do live in the Ozarks, but they are scarce and local on these clear, rocky streams. They are far more common in the lowland swamps of southeastern Missouri and eastern Arkansas. The venomous snake a camper is more likely to meet is the copperhead, which lives in the wooded hillsides and around campsites, not in the water.
AdvertisementThe floating season runs from May through September, and that is also when the snakes are most active.
What you will seeNorthern water snakes on gravel bars and tree roots. Wear river shoes, and use a flashlight around camp after dark, when copperheads are moving.
The short version
Seeing snakes at the water's edge is a sign of a healthy lake or river. They are there because the fish and frogs are there. In every one of these places, harmless water snakes far outnumber venomous ones, and in several, including the Lake Erie islands, there are no venomous snakes at all.
The habits that keep you safe are simple. Look where you step on banks and boat ramps. Do not reach under logs, ledges or docks. Keep your boat clear of low branches. Let basking snakes be, and never try to catch or kill one. Most will slip into the water long before you get close.
If someone is bitten by a snake that might be a cottonmouth, keep the person calm and the limb still, remove rings and anything tight, and call 911 or Poison Control at 1-800-222-1222. Do not cut, suck, ice or bind the wound. The hospital has the antivenom, and getting there is the only first aid that matters.
Last updated . This article is for general information. Wild animals are unpredictable, so follow local wildlife and park guidance.
