When Do Snakes Come Out in North Dakota? Snake Season Explained

North Dakota is one of the least snake-diverse states in the country, but that doesn’t mean you won’t cross paths with one while hiking the Badlands, fishing a prairie lake, or walking your property in the western counties. Knowing when snakes come out — and where they tend to be — makes every outdoor experience safer and less stressful.

In this guide, you’ll learn exactly when snake season starts and ends in North Dakota, which months carry the highest activity, what species you’re likely to encounter, and what to do if you come face to face with one. Whether you’re a hiker, a homeowner, or just curious, understanding North Dakota’s snake calendar helps you stay calm and prepared.

When Snake Season Starts and Ends in North Dakota

Snake season in North Dakota is tightly tied to temperature. Cold-blooded animals like snakes can’t be active all winter long in cold climates because they need the sun’s heat to support their bodily functions. North Dakota’s snakes are most active between April and late October when the days are warm enough to heat their bodies.

During the colder months, snakes enter a state called brumation — not quite the same as mammal hibernation. Snakes are cold-blooded animals, meaning they can’t internally regulate their body temperature. As a result, they must brumate. Brumation is a period of sluggishness and reduced activity that some reptiles utilize in colder environments. Unlike a hibernating creature, snakes don’t sleep during brumation, but simply become very lethargic.

Snakes brumate in dens called hibernaculums, which can be inter-species. Snakes have no way to dig, so these hibernaculums are often underneath rocky outcrops or in underground holes. Occasionally, snakes will even take up winter residence in other animals’ homes such as abandoned prairie dog burrows.

Snake brumation can begin anytime from September to December and last until March or April, depending on the weather pattern. In North Dakota’s harsh climate, most snakes typically don’t emerge until the ground and air temperatures are reliably warm — usually mid-to-late April at the earliest.

Key Insight: Even during brumation, snakes aren’t fully dormant. Snakes may come out of brumation if a warm front changes the weather, warming their blood and making them more active. Snakes will sense when the outside air is warmer or will likely notice the weather change when leaving their den to forage. A warm February or March day can occasionally coax a snake out early.

Peak Snake Activity Months in North Dakota

While snakes can technically be spotted from April through late October, not all months carry equal risk or activity levels. The peak window for encounters is concentrated in late spring through early fall.

Snakes can usually be found out and about during sunnier months from April through October, especially near water bodies where prey is plentiful. The warmest months — June, July, and August — are when you’re most likely to encounter snakes in open terrain, along trails, and near water sources.

However, snake behavior also shifts with the heat of the day. In early spring and late fall, prairie rattlesnakes hunt for food during the day. In summer months, they take shelter from the heat by finding a shaded area or rocky outcrops. There they stay until evening when they begin their nightly wait in ambush for small mammals.

This means that during peak summer, you’re actually more likely to encounter snakes in the early morning or evening hours rather than the middle of a hot afternoon. As they are diurnal, you’re most likely to see common garter snakes from morning through late afternoon.

Pro Tip: Be especially alert in May and September. Spring emergence means snakes are actively hunting and mating after months of dormancy. Fall is when they’re traveling back to den sites, sometimes congregating in larger numbers near rocky outcrops and hillsides.

Data reveals that every one-degree Celsius increase in daily temperature leads to approximately a six percent rise in snakebites. Warmer-than-average springs and summers in North Dakota naturally push snake activity — and encounter risk — higher.

Common Snake Species in North Dakota and Their Active Seasons

There are eight confirmed snake species in North Dakota, but only one is venomous. Here’s a closer look at each species and when you’re most likely to see them.

Red-Sided Garter Snake

In North Dakota, you’ll find more red-sided garter snakes than other common garter snake subspecies; they can grow to three or four feet long. They’re long and thin with somewhat drab colors, except for the yellow to cream dorsal and flank stripes and red vertical bars on either side of their spine. These snakes eat small amphibians, fish, worms, slugs, and anything else they can overpower and swallow.

The common garter snake is the most cold-tolerant of North American snakes and is often active both earlier and later in the year than other snake species. Expect to see red-sided garter snakes from early April through late October — a longer window than most other species in the state. You can learn more about the many types of garter snakes found across North America.

Plains Garter Snake

The plains garter snake is widespread and occurs near the edges of marshes, ponds, and streams. Like other garter snakes, plains garter snakes have longitudinal stripes that run down the length of their bodies. However, these snakes have a bright orange or yellow dorsal stripe with white flank stripes.

It’s one of the most cold-tolerant snakes in the state, being active all the way from April to late October, and will often come out of its den on warmer winter days to bask in sunny places. This makes the plains garter snake one of the species you’re most likely to spot during shoulder-season outdoor activities.

Bullsnake

The bullsnake is one of the most impressive — and frequently misidentified — snakes in North Dakota. It’s a gopher snake subspecies that gets pretty big — up to eight feet long — a length which makes it one of the longest snakes in the United States.

The bullsnake lives in the southwestern half of North Dakota, typically south and west of the Missouri River. Bull snakes are often mistaken for rattlesnakes. Because of this, they are often killed. Experts warn that you shouldn’t do this because bull snakes are the natural enemies of rattlesnakes and will often drive them out of areas. Bullsnakes are active from May through September, with peak activity in summer. For more on how venomous and non-venomous snakes differ, it’s worth understanding the distinction before reacting to any encounter.

Smooth Green Snake

Another small snake native to North Dakota is the smooth green snake. These snakes are usually just about a foot and a half long, although they can grow up to two feet long. Very shy and nonaggressive, smooth green snakes are harmless to people and mainly eat insects and worms.

Smooth green snakes are bright green, similar to the color of an unripe banana, and some have a bit of yellow near the belly scales. As brightly colored as they are, you’d think they’d be easier to spot. However, their color helps them blend into the grass and surface debris where they spend most of their lives. Active from May through early October, they’re most often seen in grassy upland areas. If you’re curious about similar species further west, check out this guide to green snakes in South Dakota.

Eastern Yellow-Bellied Racer

Racers are more common in the western half of North Dakota, and often cruise through brush and grasslands, “periscoping” their heads up to see above the grass. They’re curious and sometimes cruise up to people, startling them. However, these harmless snakes take off as soon as they realize you’re too big to eat.

Racers are active from May through September. They’re fast, diurnal, and highly visible during midday in open terrain. Racers eat anything they can overpower, which can mean rodents and birds or even other snakes, including venomous snakes.

Plains Hognose Snake

The plains hognose snake lives in scattered populations throughout North Dakota, typically in the Badlands and along sandy rivers. Plains hognose snakes are relatively small but muscular for their size, only growing to about two feet long. They have light base colors with darker spots; their pattern is similar enough to rattlesnakes that some people mistake them for venomous snakes — however, they’re harmless to people. These snakes love loose, sandy soil and use their upturned rostral scale to help them dig in the dirt.

When threatened, plains hognose snakes start out by spreading a small cobra-like hood and puffing themselves up — an impressive but harmless bluff. Active from May through early October, sightings are most common in sandy, open habitats.

Northern Red-Bellied Snake

Red-bellied snakes can be found in the eastern half of North Dakota and are the state’s smallest snake, reaching lengths of only 8–10 inches. While their backs vary in color from light to dark brown, gray, or chestnut, they have bright red to salmon-colored bellies. When feeling threatened, they will curl their lips upward to show off their tiny teeth, which is thought to be an attempt to intimidate the perceived threat.

They spend most of their time hiding under leaf litter, rotten logs, and other moist locations. Red-bellied snakes aren’t aggressive, certainly not venomous, and almost never try to bite when you pick one up. Their active season runs from May through September.

Important Note: Several non-venomous species in North Dakota — including the bullsnake and the plains hognose snake — can mimic rattlesnake behavior by coiling, hissing, and vibrating their tails. All snakes can make their head look bigger when they feel threatened. That triangular shape doesn’t necessarily indicate venomous — just scared. Always observe from a safe distance before drawing conclusions.

Venomous Snakes in North Dakota and When to Watch For Them

North Dakota keeps things relatively simple when it comes to venomous snakes. The prairie rattlesnake is North Dakota’s only venomous snake. There are no copperheads, cottonmouths, or coral snakes in the state — if you’ve wondered about the latter, you can confirm that there are no coral snakes in North Dakota.

Prairie Rattlesnake (Crotalus viridis)

Prairie rattlesnakes can grow up to 5 feet long. This species has a triangular head and a body covered in dark blotches which gradually turn into rings as they near the tail. Their color varies from greenish-gray, brown, or red, to all brown. They have dark, oval blotches surrounded by white markings. Rattlesnakes are found in grasslands and sagebrush areas, as well as high rocky ledges of buttes.

As the state’s only venomous species, the prairie rattlesnake lives in the southern regions of North Dakota. This snake lives in the southwestern regions of the state. Although occasionally they may travel north, prairie rattlesnakes primarily live on the south side of the Missouri River.

In terms of timing, snakes typically come out of hibernaculums and return to their summer activity in April or May when the weather is warm enough. At this point, they return to active hunting and mating if they are sexually mature. Prairie rattlesnakes remain active through September, with some individuals observed as late as October in warmer years.

Common Mistake: Assuming that rattlesnakes only live in the Badlands. Rattlesnakes have also expanded their traditional range to some areas east of the Missouri River, including Burleigh and Emmons counties, where numerous sightings and encounters are reported each year. Always stay alert, even if you’re not in traditionally “snake country.”

The bite of the prairie rattlesnake contains powerful venom which is both hemotoxic and neurotoxic and causes serious tissue damage. This is not a snake to approach, handle, or provoke under any circumstances. For a broader perspective on how the prairie rattlesnake compares to other dangerous species, see this overview of the most venomous snakes in North America.

According to NDSU research, there are about 7,500 snake bites a year in the U.S. and 60% involve males ages 17 to 27. Thirty percent of those involve alcohol. Only about 15% of bites are what researchers call legitimate bites — meaning people are not actually messing with the snake. The takeaway: most bites are preventable.

Where Snakes Are Most Commonly Found in North Dakota

Understanding the habitat preferences of North Dakota’s snakes helps you know where to be most cautious. Different species gravitate toward different environments, but a few key settings stand out as high-activity zones.

Rocky Outcrops and Badlands Formations

The rugged terrain of western North Dakota — particularly around Theodore Roosevelt National Park — is prime snake habitat. Prairie rattlesnakes often seek out spots where they are well-hidden and can be found under thick prairie grasses or in shaded badlands formations. Rocky ledges provide ideal basking surfaces and offer natural shelter from predators.

Prairie Grasslands and Sagebrush Flats

Although rattlesnakes enjoy open grasslands and prairies, they may also seek out forested environments. The open prairie is also home to bullsnakes, racers, and garter snakes. Snakes in North Dakota run on external warmth, so a sandy beach or riprap dam becomes a natural solar panel, bringing bodies up to hunting speed in minutes. Water edges concentrate life — frogs, minnows, and especially mice drawn to campsites and grain fields — so a single cove can support garter snakes, bull snakes, and even rattlesnakes in the same afternoon.

Near Water Sources

Lakes, rivers, marshes, and pond edges are productive hunting grounds for multiple snake species. Snakes live in a wide variety of habitats but are most often found near a permanent water source such as streams and rivers. Garter snakes in particular concentrate around wetlands and lake shores, while bullsnakes and rattlesnakes may patrol water edges in search of rodents and frogs.

Sandy Soil Areas

Plains hognose snakes prefer dry, sandy or gravelly areas in grassland, open sand prairies, or sand dunes. Sometimes mixed forest habitats and cropland may be used. Plains hog-nosed snakes are most often encountered in sandy habitats along rivers and in the badlands.

Agricultural Land and Abandoned Structures

Snakes are also drawn to farm fields and old buildings where rodent populations are high. Snakes often nest in tall grass, piles of debris or rocks, lumber stacks, and areas with frequent mice or rat activity. If you’re working on rural property — especially in the southwestern counties — take extra care around woodpiles, old machinery, and sheds. Areas of concern include crawl spaces, sheds and garages, electrical and boiler rooms, elevator shafts, and seldom-used storage spaces.

Pro Tip: Ensure that the grass on your property is well maintained, all shrubbery is cut regularly, and is trimmed back a proper distance from your building. Tall grass and unruly shrubs attract rodents as well as provide superb coverage for snakes. Keeping your yard tidy is one of the most effective ways to reduce snake presence near your home.

What to Do If You Encounter a Snake in North Dakota

Most snake encounters in North Dakota are brief and uneventful — the snake wants nothing to do with you. Staying calm and following a few simple steps keeps both you and the snake safe.

Stop, Observe, and Give Space

The moment you spot a snake, stop moving. Give the snake room to move away on its own. Rattlesnakes do not typically chase people and will most likely quickly dart or back away if spotted. However, it’s best to give them a wide berth if you do encounter one on your hike. A distance of at least 6 feet is a safe starting point — farther if you suspect it’s a rattlesnake.

Don’t Try to Handle or Kill It

This is the most important rule. Whatever you do, whether it’s a rattlesnake, a bull snake, or any reptile or amphibian, just leave it be. You can admire it from a distance, but just let it be on its own. If you don’t interact with it, it’s not going to interact with you. If you give them their space, you can enjoy them in the wild where they’re supposed to be.

Remember that snakes, rattlesnakes in particular, but all snakes in general, are an important part of our ecosystem. They control rodent populations and contribute to the health of the prairie environment. Killing a non-venomous snake like a bullsnake actually removes a natural check on rattlesnake populations in the area. For a sense of how rattlesnakes compare to truly dangerous species globally, see this list of the most venomous snakes in the world.

Identify the Snake If You Can — Safely

If you can observe the snake from a safe distance, try to note a few identifying features: body color, pattern, head shape, and whether a rattle is present. Rattlesnakes are pit vipers. They use specialized organs to detect heat. These pits, found below and in front of the eye, are placed at different positions on either side of the snake’s head. A triangular head and visible rattle are the clearest signs of a prairie rattlesnake — though remember that bullsnakes and hognose snakes can mimic this appearance.

If you’re unsure, treat every snake as potentially venomous and keep your distance. You can also check resources like the North Dakota Herp Atlas for species identification help.

If Bitten by a Venomous Snake

• Call 911 or get to an emergency room immediately — do not wait for symptoms to develop.
• Keep the bitten limb at or below heart level and stay as calm as possible to slow venom spread.
• Do not cut the wound, attempt to suck out venom, apply a tourniquet, or use ice.
• Remove any tight clothing or jewelry near the bite site in case of swelling.
• Try to note the snake’s appearance so medical staff can identify the species and administer the correct antivenin.

If you or your dog gets bit, the hospitals in the bigger cities can treat you, and the vets in those bigger cities can treat your dog as well, although antivenin isn’t cheap. Acting quickly and calmly is the most important thing you can do.

Important Note: Never attempt to handle a snake — even a dead one. Severed rattlesnake heads can still deliver a reflex bite for up to an hour after death. The safest approach is always to observe from a distance and let the snake move on.

Preventive Habits for Outdoor Activities

A few simple habits dramatically reduce your risk of an unwanted snake encounter in North Dakota:

• Wear closed-toe boots when hiking, especially in rocky or grassy terrain in western ND.
• Don’t step over rocks or logs without looking first. Mind yourself around shady, brushy areas on hot sunny days. Pay attention around prairie dog towns, as rattlesnakes hunt in them.
• Stay on marked trails when hiking in the Badlands or Theodore Roosevelt National Park.
• Avoid reaching into holes, under rocks, or into brush piles without checking first.
• Keep pets on a leash in known snake habitat areas — dogs are naturally curious and often get bitten on the nose or face.

Understanding North Dakota’s snake season — from the first warm days of April through the cooling winds of October — gives you the knowledge to enjoy the outdoors confidently. Whether real or mythical, the snakes of North Dakota have a major impact on the ecosystem, often eating mice, rats, and other small rodents that can wreak havoc if not kept in check by their natural predators. Respect their role, give them space, and you’ll find that sharing the landscape with these creatures is far less intimidating than it sounds. For more reading on snake diversity across the region, explore our guides on types of snakes in North Carolina and coral snakes in South Dakota.