The different types of snakes in New Hampshire range from a backyard garter snake sliding under a woodpile to a rattlesnake so rare that wildlife biologists keep its exact location a closely guarded secret. New Hampshire Fish and Game confirms there are 11 species of snakes that are native to New Hampshire, and five of those species were identified as being in greatest need of conservation in the state’s Wildlife Action Plan.
This guide to common snakes in New Hampshire covers the six you are most likely to encounter while hiking, gardening, or exploring a stone wall: the garter snake, timber rattlesnake, eastern hognose snake, northern black racer, smooth green snake, and ribbon snake. Knowing basic New Hampshire snake identification can turn a startling moment into an interesting one, since nearly all of these animals are harmless to people.
| Snake | Venomous | Typical Length | Conservation Status |
|---|---|---|---|
| Garter Snake | No | 23–30 in (up to 5 ft) | Common, widespread |
| Timber Rattlesnake | Yes | 36–60 in | State Endangered |
| Eastern Hognose Snake | No (mild venom for prey) | 20–33 in | Species of Greatest Conservation Need |
| Northern Black Racer | No | 4–5 ft | Species of Greatest Conservation Need |
| Smooth Green Snake | No | Small, slender | Species of Greatest Conservation Need |
| Ribbon Snake | No | 16–35 in | Species of Greatest Conservation Need |
1. Garter Snake
The garter snake, Thamnophis sirtalis, is the snake most New Hampshire residents actually meet, since this species is common and widespread across the state. It typically shows up in yards, stone walls, and compost piles because it hunts the slugs, worms, and insects that gather in those spots.
Identification is straightforward: common garter snakes range from dark olive-green to brown or black with a distinctive yellow stripe running the length of their body. According to SnakeTracks, adults typically measure 23 to 30 inches, though some individuals can grow up to 5 feet, and the species is completely harmless to humans.
New Hampshire also hosts a coastal subspecies worth knowing about: the maritime garter snake (Thamnophis sirtalis pallidula) occurs alongside the more familiar eastern garter snake. Readers curious about how this species compares to its relatives across the country can explore the full range of types of garter snakes found throughout North America.
2. Timber Rattlesnake
The timber rattlesnake, Crotalus horridus, is the one species on this list that genuinely warrants caution, since it is the rarely-seen timber rattlesnake, the only venomous snake native to New Hampshire. It is also the state’s most endangered animal, not its most dangerous one, because actually encountering one is extraordinarily unlikely.
According to New Hampshire Fish and Game’s species profile, the timber rattlesnake carries a State Endangered conservation status and a State Rank of Critically Imperiled (S1), with a historic range stretching from the Massachusetts border up to the White Mountains. Today, only one known population remains in the state, and it lives on rocky, south-facing hillsides in wooded areas exposed to abundant sunlight.
Physically, it is a large, thick snake measuring 36 to 60 inches with a large triangular head, keeled scales, and a blunt rattle at the end of its tail. Interestingly, most timber rattlesnakes in New Hampshire are “black phase,” meaning the brown cross-bands are hard to see and the snake can appear almost entirely black.
Pro Tip: A triangular head, vertical pupils, and a rattle are the quickest way to rule out a timber rattlesnake. Garter and ribbon snakes have narrow, rounded heads and no rattle at all.
NH Audubon notes that the species is critically endangered with just one known population left in the state, yet these snakes are shy, non-aggressive, and play a key role in controlling rodent populations. The organization urges residents to avoid disturbing rocky habitats and share facts rather than fear to help protect one of the state’s most threatened reptiles. For readers wondering exactly how many types of rattlesnakes exist across the country, or how New Hampshire’s lone species stacks up against the desert species found in places like the rattlesnakes of Arizona, the contrast in habitat and climate is striking.
Important Note: The timber rattlesnake is protected by New Hampshire law. It is illegal to kill, capture, or disturb one. If you believe you have spotted a rattlesnake in the wild, keep your distance and report the sighting to New Hampshire Fish and Game rather than approaching it.
3. Eastern Hognose Snake
The eastern hognose snake, Heterodon platirhinos, is one of the state’s more theatrical reptiles. You can recognize it by the upturned nasal scales that give it a swine-like appearance, which is exactly how it earned its common name.
Coloration varies more in this species than in almost any other New Hampshire snake. Eastern hognose snakes run 20 to 33 inches long and can show red, black, grey, or brown bodies with dark markings, and according to GreenNature’s New Hampshire snake guide, all hognose species have thick bodies that can reach four feet, with the eastern hognose being the most wide-ranging of the group.
When threatened, this species skips fighting altogether and performs one of the more convincing acts in the animal kingdom: flattening its body, hissing, and then rolling over to play dead with its mouth hanging open. Readers who want to see how this behavior compares across other reptiles can check out a broader look at snakes that play dead. New Hampshire’s Wildlife Action Plan lists the eastern hognose as a species in greatest conservation need, alongside the timber rattlesnake, northern black racer, smooth green snake, and ribbon snake.
4. Northern Black Racer
The northern black racer, Coluber constrictor constrictor, lives up to its name on both counts. It is dark green or black in color and moves very fast, often disappearing into brush before a hiker gets a second look.
Range matters with this species. In New Hampshire, black racers are usually found south of the White Mountains, where they favor areas with heavy brush, thick grasslands, or the edges of forested land. Beyond the state’s borders, GreenNature notes that black racers inhabit most areas in the East, from southern Maine to the Florida Keys, giving them one of the widest ranges of any snake on this list.
Size-wise, these snakes are not especially long; the biggest individuals run just over five feet, though most fall between four and five feet. Since their range extends north of the Granite State, readers comparing regional populations may also want to review the snakes found in Maine, where racers share similar habitat along the coast and southern interior.
5. Smooth Green Snake
The smooth green snake, Opheodrys vernalis, is one of the least-seen snakes in New Hampshire despite being, by most accounts, one of the prettiest. Its bright green back and pale underside make it nearly invisible against grass and low vegetation, which is likely why encounters are so infrequent even in areas where the species is present.
This snake is almost entirely insectivorous, feeding on crickets, caterpillars, and spiders rather than the small mammals and amphibians that make up the diet of larger New Hampshire snakes. It favors open, grassy meadows, old fields, and the edges of wetlands rather than deep forest. New Hampshire’s Wildlife Action Plan lists the smooth green snake as a species in greatest need of conservation, grouping it with the timber rattlesnake, eastern hognose, black racer, and ribbon snake as reptiles whose populations and distribution remain poorly understood statewide.
Key Insight: Four of the six snakes covered in this guide — the timber rattlesnake, eastern hognose, black racer, and smooth green snake — share the same conservation designation. That overlap tells researchers these species are reacting to similar pressures, likely habitat fragmentation and development, rather than facing isolated threats.
6. Ribbon Snake
The ribbon snake, Thamnophis sauritus, is frequently mistaken for its cousin the garter snake, and the confusion is understandable since both belong to the same genus. GreenNature points out that the eastern ribbon snake has a distinct pattern on the body in addition to the common stripes that both species share, which is one of the clearer ways to tell them apart in the field.
According to SnakeTracks, adult ribbon snakes typically measure 16 to 35 inches, and the species tends to be noticeably slimmer than a garter snake of comparable length. They are usually found in woodlands, fields, under logs, and in forests, almost always near the wetlands, ponds, or slow streams where their amphibian prey lives.
Like the smooth green snake and black racer, the ribbon snake is listed as a species of greatest conservation need in New Hampshire. If you are trying to sort out every patterned snake turning up in your yard, it also helps to know the other species sharing the same habitat, including the milk snake; a closer look at the different types of milk snakes can help separate that species’ bold blotches from a ribbon snake’s slim stripes.
Staying Safe Around New Hampshire’s Snakes
Out of the six species covered here, only the timber rattlesnake carries venom, and even that species would rather retreat than strike. The simplest safety rule for anyone exploring New Hampshire’s woods, fields, or wetlands is to give any snake room to move away rather than attempting to handle or corner it.
- Watch where you place your hands and feet on rocky, south-facing ledges, which is prime timber rattlesnake habitat.
- Leave logs, brush piles, and stone walls undisturbed when possible, since several species use them for cover.
- Never attempt to kill a snake you cannot positively identify; five of the state’s eleven native species are protected under conservation listings.
- If bitten by any snake, seek medical attention promptly and try to remember the snake’s basic appearance rather than attempting to capture it.
This article is intended for general wildlife education and is not a substitute for professional medical or emergency guidance. If you are ever uncertain whether a snake is dangerous, treat the encounter with caution and contact local wildlife authorities.
New Hampshire’s snake population is modest compared to warmer states, but the diversity among these six species shows how much variety even a small, cold-climate state can hold. Readers interested in how snake diversity shifts with geography and climate might enjoy comparing notes with neighboring and far-flung states, from the snakes of Maryland to the snakes of Delaware and the considerably more snake-rich snakes of South Carolina. Whatever species turns up in your yard or on your next hike, a little New Hampshire snake identification goes a long way toward replacing fear with curiosity.