**Snake Identification Chart — Venomous or Harmless?**

> Free snake identification key for 28 North American snakes. Filter by pattern, size and region, with every venomous species flagged beside its look-alikes.

Source: https://orvik.app/tools/snake-identifier/ · updated: 2026-09-04

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Animals

# What snake did I just see?

Of roughly 150 snake species in the United States, about 22 are venomous, and they belong to just four groups: **rattlesnakes, copperheads, cottonmouths and coral snakes**. Everything else on this list is harmless. Filter by pattern and region — those two together settle most sightings without anyone needing to get close.

Entries **28** Filters **5** Updated **2026-09-04** Cost **Free, no account**

**Identify from a distance and leave it alone.** Most bites happen to people who were handling, killing or moving a snake, and a severed head can still envenomate by reflex for up to an hour. If someone is bitten: get away from the snake, keep the limb still and below heart level, remove rings and watches, and go to hospital. **Do not** cut, suck, apply ice, use a tourniquet or take alcohol — every one of those makes the outcome worse. A photograph from a safe distance helps the hospital; a captured snake does not.

Narrow it down

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Search snakes by name

Pattern

Plain, one colour Stripes running lengthwise Blotches or saddles down the back Rings or bands around the body Diamonds Hourglass or dumbbell crossbands Speckled or checkered

Venom

Venomous Harmless

Adult length

Under 50 cm / 20 in 50–100 cm / 20–40 in 1–1.5 m / 40–60 in Over 1.5 m / 5 ft

Where you are

Northeast Southeast Midwest Southwest West and Pacific

Habitat

In or beside water Woodland or leaf litter Field, prairie or desert Garden, garage or under something Rocky slope or ledge

Showing all 28 snakes

1. ### Copperhead Can injure you Agkistrodon contortrix Tan to pinkish with dark crossbands shaped like an hourglass — wide on the sides, pinched narrow across the spine. Viewed from directly above, the bands look like a row of Hershey's Kisses. Size 60–90 cm Where Massachusetts to Florida, west to Texas and Nebraska. Confused with Northern water snake, eastern milk snake and juvenile rat snake. On all of those the dark markings are wide at the spine and narrow at the sides — the exact reverse of a copperhead. Risk Accounts for more venomous snakebites than any other US species, and the fewest deaths. Bites are painful and destroy local tissue; antivenom is often not needed but assessment always is. In the record 23,082 georeferenced records · half of them Apr–Jul · most distinctive in September · mostly from the United States [check on GBIF](https://www.gbif.org/species/9215881)

2. ### Cottonmouth Can injure you Agkistrodon piscivorus Heavy-bodied, dark olive to almost black with faded bands, and a broad dark stripe through the eye. Gapes to show a startlingly white mouth lining when threatened, and swims with its whole body riding on the surface. Size 75–120 cm Where The southeastern US coastal plain, north to Virginia and west to Texas. Confused with Harmless water snakes, which swim with only the head above water and flee rather than stand their ground. Risk Venom is cytotoxic and destroys tissue. It is also the species most often misidentified — most "cottonmouths" reported outside the range map are harmless water snakes. In the record 20,525 georeferenced records · half of them Mar–Jun · most distinctive in December · mostly from the United States [check on GBIF](https://www.gbif.org/species/9105722)

3. ### Timber rattlesnake Can injure you Crotalus horridus Heavy-bodied, yellow, grey or near-black with dark V-shaped crossbands and a solid black tail ending in a rattle. Often lies motionless in leaf litter for hours. Size 90–150 cm Where The eastern US from New England to Texas. Risk Long fangs and a large venom yield. Generally reluctant to strike and frequently does not rattle before it does. In the record 12,293 georeferenced records · half of them May–Jul · most distinctive in July · mostly from the United States [check on GBIF](https://www.gbif.org/species/2444468)

4. ### Eastern diamondback rattlesnake Can injure you Crotalus adamanteus The largest venomous snake in North America: bold dark diamonds outlined in cream on a brown-olive ground, and two pale diagonal stripes across the side of the face. Size 1.2–1.8 m, exceptionally 2.4 m Where The coastal plain from North Carolina to Louisiana. Risk The most dangerous snake in the United States by venom yield and body size. Give it a very wide berth. In the record 4,259 georeferenced records · half of them Apr–Sep · most distinctive in January · mostly from the United States [check on GBIF](https://www.gbif.org/species/2444432)

5. ### Western diamondback rattlesnake Can injure you Crotalus atrox Dusty grey-brown with faint diamonds and — the diagnostic feature — a tail ringed in equal black and white bands like a coach whip, immediately before the rattle. Size 90–150 cm Where Texas and Oklahoma west to Arizona and southern California. Confused with Mojave rattlesnake, whose white tail bands are noticeably wider than the black ones and whose venom is far more dangerous. Risk Responsible for the most snakebite fatalities in the US. Stands its ground and rattles loudly. In the record 28,016 georeferenced records · half of them May–Aug · most distinctive in November · mostly from the United States [check on GBIF](https://www.gbif.org/species/2444356)

6. behind the corner of the mouth."> ### Mojave rattlesnake Can injure you Crotalus scutulatus Looks like a small western diamondback, but the white tail bands are distinctly wider than the black ones, and a pale stripe runs behind the eye to *behind* the corner of the mouth. Size 60–110 cm Where The Mojave and Sonoran deserts of California, Nevada, Arizona, New Mexico and west Texas. Risk Some populations carry a potent neurotoxin in addition to the usual tissue-destroying venom, and symptoms can be delayed. Any suspected Mojave bite is a hospital emergency regardless of how the wound looks. In the record 8,048 georeferenced records · half of them Jun–Aug · most distinctive in August · mostly from the United States [check on GBIF](https://www.gbif.org/species/2444480)

7. ### Prairie rattlesnake Can injure you Crotalus viridis Greenish-grey to light brown with dark oval blotches edged in white down the back, and two pale stripes on the side of the face. The default rattlesnake across the plains. Size 90–115 cm Where The Great Plains from Canada to Mexico, and the Rockies. In the record 15,687 georeferenced records · half of them Apr–Jul · most distinctive in December · mostly from the United States [check on GBIF](https://www.gbif.org/species/8945077)

8. ### Western rattlesnake Can injure you Crotalus oreganus Brown to olive with dark blotches that become bands towards the tail, and a rattle. The only venomous snake across most of the Pacific states. Size 75–115 cm Where California, Oregon, Washington, Idaho and Nevada. In the record 30,556 georeferenced records · half of them Apr–Jun · most distinctive in February · mostly from the United States [check on GBIF](https://www.gbif.org/species/2444446)

9. ### Sidewinder Can injure you Crotalus cerastes Small, sand-coloured, with raised horn-like scales over each eye, and it moves sideways in loops leaving a J-shaped track in the sand. Nothing else does either. Size 45–75 cm Where The deserts of southeastern California, Nevada, Arizona and Utah. Risk Venomous but small; bites are painful and rarely life-threatening in a healthy adult. In the record 8,565 georeferenced records · half of them Mar–May · most distinctive in April · mostly from the United States [check on GBIF](https://www.gbif.org/species/2444360)

10. ### Pygmy rattlesnake Can injure you Sistrurus miliarius Small and grey with a row of dark blotches and an orange stripe down the spine. The rattle is so tiny it sounds like an insect, and often goes unheard entirely. Size 35–60 cm Where The southeastern US from North Carolina to Texas. Risk Small venom yield, but bites cause severe local tissue damage and are frequently underestimated. In the record 5,531 georeferenced records · half of them May–Sep · most distinctive in December · mostly from the United States [check on GBIF](https://www.gbif.org/species/2444222)

11. ### Massasauga Can injure you Sistrurus catenatus Stout, grey with large chocolate-brown blotches, in wet grassland. Federally threatened and rarely seen; a small rattle that is easy to miss. Size 45–75 cm Where Wet prairie and fen from Ontario and New York west to Iowa and Missouri. Risk Protected across most of its range. Report a sighting to a state wildlife agency rather than moving the animal. In the record 4,175 georeferenced records · half of them Jul–Aug · most distinctive in August · mostly from Canada [check on GBIF](https://www.gbif.org/species/9223124)

12. ### Eastern coral snake Can injure you Micrurus fulvius Slender, glossy, with complete rings of red, yellow and black all the way around the body, a blunt black snout, and red rings touching yellow rings. Size 60–75 cm Where Florida and the coastal plain west to Louisiana. Confused with Scarlet kingsnake and scarlet snake, on which red touches black. In the United States only: red touches yellow, kill a fellow; red touches black, friend of Jack. The rhyme fails in Latin America. Risk A neurotoxin, unlike every other US venomous snake. Symptoms can be delayed 12 hours or more and then progress to respiratory failure. Any suspected coral snake bite is an emergency even with no pain and no visible wound. In the record 2,060 georeferenced records · half of them Mar–Jul · most distinctive in January · mostly from the United States [check on GBIF](https://www.gbif.org/species/9173089)

13. wide at the spine and narrow at the sides — the reverse of a copperhead — becoming almost uniformly dark with age. swims with only its head above water."> ### Northern water snake Nerodia sipedon Heavy-bodied and dark brown with crossbands that are **wide at the spine and narrow at the sides** — the reverse of a copperhead — becoming almost uniformly dark with age. Swims with only its head above water. Size 60–120 cm Where The eastern and central United States. Confused with Killed constantly as a cottonmouth or copperhead. A round pupil, a narrow head and a body that flees rather than gapes are all it takes to tell. In the record 72,882 georeferenced records · half of them Apr–Jun · most distinctive in May · mostly from the United States [check on GBIF](https://www.gbif.org/species/5223334)

14. ### Common garter snake Thamnophis sirtalis Three pale lengthwise stripes — one down the spine, one on each side — over a dark checkered ground. The default garden snake across the continent. Size 45–90 cm Where The most widely distributed snake in North America. In the record 169,200 georeferenced records · half of them Mar–Jun · most distinctive in August · mostly from the United States [check on GBIF](https://www.gbif.org/species/2457522)

15. ### Eastern ratsnake Pantherophis alleghaniensis Long, glossy and near-black as an adult with a white chin and throat, climbing walls and trees easily. Its cross-section is loaf-shaped — flat belly, angled sides — rather than round. Size 1.2–1.8 m Where The eastern United States. Confused with Juveniles are grey with dark blotches and are mistaken for copperheads every summer. The blotches are wide at the spine, not pinched. In the record 41,026 georeferenced records · half of them Apr–Jun · most distinctive in June · mostly from the United States [check on GBIF](https://www.gbif.org/species/7453543)

16. ### Corn snake Pantherophis guttatus Orange to rust with bold red saddles outlined in black, a spear-point mark on the head, and a black-and-white chequerboard belly — the belly is diagnostic and no venomous species has it. Size 75–120 cm Where The southeastern United States. In the record 10,069 georeferenced records · half of them Mar–Jun · most distinctive in January · mostly from the United States [check on GBIF](https://www.gbif.org/species/2455615)

17. ### Eastern milk snake Lampropeltis triangulum Grey with red-brown blotches edged in black and a pale Y or V on the back of the head. Found under boards, in barns and in basements, which is where the copperhead confusion starts. Size 60–90 cm Where The eastern and central United States. In the record 21,945 georeferenced records · half of them May–Jun · most distinctive in June · mostly from the United States [check on GBIF](https://www.gbif.org/species/5224503)

18. ### Eastern kingsnake Lampropeltis getula Glossy black with narrow cream chain-link bands. It eats other snakes, including copperheads and rattlesnakes, and is largely immune to their venom. Size 90–120 cm Where The eastern and southeastern United States. In the record 9,460 georeferenced records · half of them Apr–Jun · most distinctive in January · mostly from the United States [check on GBIF](https://www.gbif.org/species/9799308)

19. red touching black. a harmless mimic of the coral snake."> ### Scarlet kingsnake Lampropeltis elapsoides Red, black and yellow bands with a red snout and, crucially, **red touching black**. A harmless mimic of the coral snake. Size 35–50 cm Where The southeastern United States. In the record 1,234 georeferenced records · half of them Feb–May · most distinctive in January · mostly from the United States [check on GBIF](https://www.gbif.org/species/7794320)

20. ### Black racer Coluber constrictor Uniform satin black with a white chin, slender and very fast, holding its head up off the ground as it moves. Where a ratsnake climbs, a racer runs. Size 90–150 cm Where Most of the United States. In the record 48,933 georeferenced records · half of them Apr–Jun · most distinctive in January · mostly from the United States [check on GBIF](https://www.gbif.org/species/6161776)

21. ### Coachwhip Masticophis flagellum Very long and whip-thin, dark at the head fading to tan at the tail, with scales that look braided like a whip. Extremely fast in open ground. Size 1.2–1.8 m Where The southern United States. In the record 19,174 georeferenced records · half of them Apr–Jun · most distinctive in April · mostly from the United States [check on GBIF](https://www.gbif.org/species/8433585)

22. ### Gopher snake and bullsnake Pituophis catenifer Big, tan with dark brown saddles, and an impressive bluff: it flattens its head into a triangle, hisses loudly and vibrates its tail in dry leaves to sound exactly like a rattlesnake. It has no rattle. Size 1.2–1.8 m Where Western and central North America. Confused with The single most-killed harmless snake in the American West, precisely because the bluff works. Look for the absence of a rattle and for a round pupil. In the record 64,677 georeferenced records · half of them Apr–Jun · most distinctive in May · mostly from the United States [check on GBIF](https://www.gbif.org/species/2453826)

23. ### Eastern hognose snake Heterodon platirhinos Stout with an upturned shovel-like snout. When cornered it flattens its neck like a cobra, hisses, strikes with its mouth closed, and if that fails rolls over and plays dead with its tongue hanging out. Size 50–90 cm Where The eastern United States. In the record 11,733 georeferenced records · half of them Mar–Jun · most distinctive in September · mostly from the United States [check on GBIF](https://www.gbif.org/species/5223730)

24. ### Ring-necked snake Diadophis punctatus Small, slate grey with a bright yellow or orange ring around the neck and a vivid orange belly it shows by curling its tail when alarmed. Found under logs, rocks and paving. Size 25–40 cm Where Most of the United States. In the record 44,522 georeferenced records · half of them Apr–Jun · most distinctive in February · mostly from the United States [check on GBIF](https://www.gbif.org/species/8763701)

25. ### DeKay's brown snake Storeria dekayi Tiny, plain grey-brown with a pale stripe down the back edged with small dark dots. Common in gardens, compost heaps and city parks and almost always mistaken for a baby of something else. Size 23–33 cm Where The eastern and central United States, including dense cities. In the record 49,081 georeferenced records · half of them Mar–Jun · most distinctive in November · mostly from the United States [check on GBIF](https://www.gbif.org/species/9056579)

26. ### Rough green snake Opheodrys aestivus Slender, uniform bright leaf-green above and pale yellow below, moving through shrubs and vines. Eats insects and is entirely harmless. Size 55–80 cm Where The southeastern United States. In the record 18,637 georeferenced records · half of them Mar–Jun · most distinctive in October · mostly from the United States [check on GBIF](https://www.gbif.org/species/8984671)

27. ### Eastern indigo snake Drymarchon couperi The longest native snake in the United States: glossy blue-black with an orange-red chin and throat, thick-bodied and diurnal. Size 1.5–2.4 m Where Southern Georgia and Florida. Risk Federally threatened. Killing or harassing one is a federal offence. In the record 145 georeferenced records · half of them Nov–Mar · most distinctive in December · mostly from the United States [check on GBIF](https://www.gbif.org/species/2452317)

28. ### Common watersnake of the West Thamnophis and Nerodia species Striped or blotched snakes swimming in western waters are garter and water snakes — there is no cottonmouth west of central Texas, so any snake in water in California, Oregon or Arizona is harmless. Size 50–110 cm Where Streams and ponds of the western United States. In the record 329,102 georeferenced records · half of them Apr–Jul · most distinctive in August · mostly from the United States [check on GBIF](https://www.gbif.org/species/2457825)

Nothing in this key matches every filter at once. That usually means one observation is
off — a colour read in shade, or a size guessed rather than measured. Clear the filter you
are least sure about and look again.

## The four venomous groups, and nothing else

Learning twenty-two venomous species is unnecessary. Learning four groups is enough, and each has a feature visible from several metres away.

- **Rattlesnakes** — a rattle. Sixteen species in the US, all with the same terminal segment. A snake with a rattle is a rattlesnake; a snake without one is not, however hard it vibrates its tail in leaf litter.
- **Copperhead** — hourglass crossbands, pinched narrow across the spine and wide at the sides, on a tan or pink ground. Only in the East and Midwest.
- **Cottonmouth** — heavy, dark, thick-necked, in water, in the southeastern coastal plain. Gapes to show a white mouth.
- **Coral snake** — complete rings of red, yellow and black with red touching yellow, and a black snout. Southeast and, as separate species, Arizona and Texas.

Region does more filtering than any physical character. There are no venomous snakes at all in Alaska, Hawaii or Maine. There is one venomous species — the western rattlesnake — across most of the Pacific Northwest and northern California. There is no cottonmouth west of central Texas, so a snake swimming in a Californian creek is harmless, full stop.

## The rules you were taught that do not work

Several widely repeated tests are unreliable, and two of them require standing close enough to be bitten.

**Triangular head.** The most repeated and the most misleading. Water snakes, hognose snakes and gopher snakes all flatten their heads into a triangle when threatened, which is precisely when you are looking at them. Meanwhile the coral snake — the most dangerous venomous snake in the country by venom type — has a narrow head no wider than its neck.

**Vertical pupils.** True of pit vipers and false of coral snakes, which have round pupils. It also requires you to be close enough to see a pupil, in good light, on a moving animal. Do not use it.

**Tail rattling.** Many harmless snakes vibrate their tails when alarmed, and in dry leaves a gopher snake or a ratsnake produces a convincing buzz. The sound is not the evidence; the rattle is.

**Aggression.** Snakes do not chase people. What is nearly always happening is that the snake is trying to reach cover and the person is standing between it and the cover. Step sideways and it goes past you.

The rhyme that *does* work, and only in the United States: **red touches yellow, kill a fellow; red touches black, friend of Jack**. It separates the eastern coral snake from the scarlet kingsnake and scarlet snake reliably within US borders. It fails completely in Central and South America, where coral snakes come in patterns the rhyme does not describe.

## The confusions that get harmless snakes killed

*The three misidentifications behind most snake killings in the United States, and the character that separates each pair.*

| Mistaken for | Usually is | The test |
| --- | --- | --- |
| Copperhead | Northern water snake, juvenile ratsnake, eastern milk snake, corn snake | Copperhead bands are *pinched narrow across the spine*; on every look-alike the dark marks are widest at the spine |
| Cottonmouth | Northern or banded water snake | Cottonmouth swims with the whole body on the surface and gapes white; a water snake swims with only its head up and flees. Also check the range map — most reports are outside it |
| Rattlesnake | Gopher snake, bullsnake, ratsnake, hognose | Look for an actual rattle. Tail-buzzing in leaves is a bluff several harmless species perform well |
| Coral snake | Scarlet kingsnake, scarlet snake | Red touching yellow is coral; red touching black is harmless. Coral snakes also have a black snout, the mimics a red one |

Killing snakes is also counterproductive on its own terms. A single ratsnake or kingsnake removes a large number of rodents a year, and kingsnakes specifically eat copperheads and rattlesnakes and are resistant to their venom. Removing the harmless snakes from a property reliably increases both the rodent population and, in time, the venomous snake population.

It is often illegal too. Several species on this list are federally or state protected — eastern indigo snake, massasauga, timber rattlesnake in several northeastern states — and in many jurisdictions killing any non-venomous native snake is an offence.

## If somebody is bitten

The current medical guidance is short, and most of it is a list of things not to do.

1. **Move away from the snake.** A second bite is a real risk, and a severed head retains a bite reflex for up to an hour.
2. **Call emergency services and get to hospital.** Antivenom is the treatment and it is only available there.
3. **Keep the person calm and still**, with the bitten limb immobilised and roughly at or below heart level.
4. **Remove rings, watches and tight clothing** immediately — swelling can be dramatic and fast.
5. **Mark the leading edge of the swelling with a pen and write the time.** This is genuinely useful to the treating team.
6. **Photograph the snake only if it can be done safely from a distance.** Do not catch or kill it; identification is helpful but not required, since US antivenom covers all pit vipers.

**Do not:** cut the wound, attempt to suck out venom, use a suction device, apply a tourniquet or constriction band, ice the limb, give alcohol or caffeine, or give aspirin or ibuprofen. Every one of these is either useless or actively harmful, and the field literature is unambiguous about it.

About a quarter of pit viper bites are dry, with no venom injected, but that cannot be determined outside a hospital. Coral snake bites deserve particular caution: the neurotoxin can produce little pain and no local swelling, and symptoms may not appear for twelve hours or more before progressing rapidly to respiratory failure. A suspected coral snake bite goes to hospital regardless of how well the person feels.

## Keeping snakes out of a garden

Snakes come for food and shelter, and both are manageable without touching a single snake.

- **Remove the rodents.** Secure feed bins, clear spilled bird seed, and compost in a closed bin. Rodents are why the snake is there.
- **Remove the shelter.** Woodpiles stacked on the ground, sheets of plywood, rock piles, dense ground cover against a foundation and long grass are all daytime retreats. Raise the woodpile and clear a strip.
- **Seal the gaps.** Anything a mouse fits through, a snake fits through. Foundation gaps, dryer vents and gaps under garage doors are the usual routes.
- **Ignore the repellents.** Mothballs, sulphur, ultrasonic devices and lime have all been tested and none works. Mothballs used outdoors are also illegal in the United States under their label instructions, and they poison children and pets.
- **Never use glue traps outdoors.** They catch birds, lizards and non-target snakes, and the animals die slowly.

If a snake is inside a building, open an exterior door and leave the room; most will leave on their own within a few hours. If it needs moving and it might be venomous, call a local wildlife removal service or a state wildlife agency. Many areas have volunteer snake relocators who will do it for free, precisely because they would rather the snake was moved than killed.

## What this key covers

28 entries: every venomous group in the United States and the harmless species most likely to be confused with them, plus the common garden and woodland snakes people photograph. That is a fraction of the roughly 150 US species — the fossorial snakes, the many *Thamnophis* forms, the regional endemics of Texas and the Southwest, and the whole Mexican fauna are absent.

Two limits worth naming. Juveniles frequently look nothing like adults: ratsnakes, racers and cottonmouths are all patterned as young and plain as adults, and a bright yellow tail tip on a young cottonmouth or copperhead is a lure for frogs. And melanistic individuals — all-black forms of normally patterned species — occur regularly in garter snakes, ratsnakes and timber rattlesnakes.

For an identification that matters, photograph from a safe distance and post it to a regional snake identification group on iNaturalist or Facebook, where herpetologists routinely answer within minutes. Include your county. Location narrows the candidates faster than any photograph.

## What the observation record shows

Every entry in this key that carries a scientific name is matched against

- [GBIF](https://www.gbif.org/), the
international register of biodiversity records, and against

- [iNaturalist](https://www.inaturalist.org/).
That puts a hard number behind 28 of the 28snakes here:
**745,515 georeferenced records** across the 27 entries that resolve to a single species, spanning 3 families, the oldest of them collected in
1930. The snapshot was taken on 2026-09-04.

That evidence is not spread evenly, and it is worth knowing before you trust a narrow
result. The five best-recorded snakes in this key hold 54%
of all the records between them: Common garter snake alone accounts for
169,200, while Eastern indigo snake has
145. A common thing is common in the data too, so
when a filter narrows to one frequent entry and one rare one, the frequent one is
usually the answer — and the record count is the quickest way to see which is which.
The same skew applies geographically: 87% of these
records come from the United States, so the key describes what is
reported there far better than it describes anywhere else.

### When these are actually reported

*Half of the 716,424 georeferenced records for these 27 snakes fall in March–June alone. The bars are the raw share by month, which mostly measures when people go looking; the line divides each month by the baseline for every species in every Orvik key, so a value above 1.0 means these snakes are reported more than the season alone explains, and it peaks in June. Source: GBIF, snapshot 2026-09-04.*

Half of every record for this group falls in March–June.
A raw month count measures two things at once — when the organism is about, and when
people are outdoors with a camera — and the second effect is large enough to give
almost anything a summer peak. The line on the figure divides each month by the
baseline for every species in every Orvik key, which answers a different question:
relative to when people record anything at all, when are these snakes recorded?
Values above 1.0 are the months that belong to this group rather than to the season.
On that measure 15 of the 27snakes here peak
outside the warm half of the year — DeKay's brown snake, Black racer, Ring-necked snake among them. Those are the ones a seasonal rule of
thumb gets wrong.

### Records behind each entry

Sorted by how much evidence exists, not by how likely you are to meet one. The peak
month is the effort-adjusted figure, and it is left blank wherever the sample is too
thin for the month-to-month wobble to mean anything.

*GBIF and iNaturalist record counts for the 28 named snakes in this key,
 snapshot 2026-09-04. Rows above species rank aggregate everything beneath them and
 are not comparable with the rest. Free to reuse with a link to this page.*

| Entry | Accepted name | Rank | GBIF records | Research-grade | Half fall in | Peak, adjusted | Most reported from |
| --- | --- | --- | --- | --- | --- | --- | --- |
| Common garter snake | [Thamnophis sirtalis](https://www.gbif.org/species/2457522) | species | 169,200 | 207,688 | Mar–Jun | August | the United States |
| Northern water snake | [Nerodia sipedon](https://www.gbif.org/species/5223334) | species | 72,882 | 97,127 | Apr–Jun | May | the United States |
| Gopher snake and bullsnake | [Pituophis catenifer](https://www.gbif.org/species/2453826) | species | 64,677 | 82,533 | Apr–Jun | May | the United States |
| DeKay's brown snake | [Storeria dekayi](https://www.gbif.org/species/9056579) | species | 49,081 | 68,747 | Mar–Jun | November | the United States |
| Black racer | [Coluber constrictor Linnaeus, 1758](https://www.gbif.org/species/6161776) | species | 48,933 | 58,543 | Apr–Jun | January | the United States |
| Ring-necked snake | [Diadophis punctatus](https://www.gbif.org/species/8763701) | species | 44,522 | 48,004 | Apr–Jun | February | the United States |
| Eastern ratsnake | [Pantherophis alleghaniensis](https://www.gbif.org/species/7453543) | species | 41,026 | 60,682 | Apr–Jun | June | the United States |
| Western rattlesnake | [Crotalus oreganus Holbrook, 1840](https://www.gbif.org/species/2444446) | species | 30,556 | 38,589 | Apr–Jun | February | the United States |
| Western diamondback rattlesnake | [Crotalus atrox Baird & Girard, 1853](https://www.gbif.org/species/2444356) | species | 28,016 | 31,562 | May–Aug | November | the United States |
| Copperhead | [Agkistrodon contortrix](https://www.gbif.org/species/9215881) | species | 23,082 | 27,766 | Apr–Jul | September | the United States |
| Eastern milk snake | [Lampropeltis triangulum](https://www.gbif.org/species/5224503) | species | 21,945 | 29,750 | May–Jun | June | the United States |
| Cottonmouth | [Agkistrodon piscivorus](https://www.gbif.org/species/9105722) | species | 20,525 | 24,500 | Mar–Jun | December | the United States |
| Coachwhip | [Masticophis flagellum](https://www.gbif.org/species/8433585) | species | 19,174 | 18,629 | Apr–Jun | April | the United States |
| Rough green snake | [Opheodrys aestivus Linnaeus, 1766](https://www.gbif.org/species/8984671) | species | 18,637 | 22,781 | Mar–Jun | October | the United States |
| Prairie rattlesnake | [Crotalus viridis Rafinesque, 1818](https://www.gbif.org/species/8945077) | species | 15,687 | 38,589 | Apr–Jul | December | the United States |
| Timber rattlesnake | [Crotalus horridus Linnaeus, 1758](https://www.gbif.org/species/2444468) | species | 12,293 | 15,680 | May–Jul | July | the United States |
| Eastern hognose snake | [Heterodon platirhinos Latreille, 1801](https://www.gbif.org/species/5223730) | species | 11,733 | 13,502 | Mar–Jun | September | the United States |
| Corn snake | [Pantherophis guttatus](https://www.gbif.org/species/2455615) | species | 10,069 | 12,362 | Mar–Jun | January | the United States |
| Eastern kingsnake | [Lampropeltis getula](https://www.gbif.org/species/9799308) | species | 9,460 | 34,229 | Apr–Jun | January | the United States |
| Sidewinder | [Crotalus cerastes Hallowell, 1854](https://www.gbif.org/species/2444360) | species | 8,565 | 5,127 | Mar–May | April | the United States |
| Mojave rattlesnake | [Crotalus scutulatus Kennicott, 1861](https://www.gbif.org/species/2444480) | species | 8,048 | 6,226 | Jun–Aug | August | the United States |
| Pygmy rattlesnake | [Sistrurus miliarius Linnaeus, 1766](https://www.gbif.org/species/2444222) | species | 5,531 | 6,178 | May–Sep | December | the United States |
| Eastern diamondback rattlesnake | [Crotalus adamanteus Palisot De Beauvois, 1799](https://www.gbif.org/species/2444432) | species | 4,259 | 4,553 | Apr–Sep | January | the United States |
| Massasauga | [Sistrurus catenatus](https://www.gbif.org/species/9223124) | species | 4,175 | 5,476 | Jul–Aug | August | Canada |
| Eastern coral snake | [Micrurus fulvius](https://www.gbif.org/species/9173089) | species | 2,060 | 4,904 | Mar–Jul | January | the United States |
| Scarlet kingsnake | [Lampropeltis elapsoides](https://www.gbif.org/species/7794320) | species | 1,234 | 1,304 | Feb–May | January | the United States |
| Eastern indigo snake | [Drymarchon couperi](https://www.gbif.org/species/2452317) | species | 145 | 276 | Nov–Mar | December | the United States |
| Common watersnake of the West | [Thamnophis Fitzinger, 1843](https://www.gbif.org/species/2457825) | genus | 329,102 | 339,462 | Apr–Jul | August | the United States |

This table is assembled from open data and is free to reuse with a link back to this
page. The snapshot behind every Orvik key is published as one downloadable file on the

- [open field data](https://orvik.app/data/) page, with each source's licence terms.

## Questions people ask about this

How do I tell a venomous snake from a harmless one?

In the United States, learn four groups rather than twenty-two species: rattlesnakes have a rattle, copperheads have hourglass crossbands pinched narrow across the spine, cottonmouths are heavy dark water snakes of the southeastern coastal plain that gape white, and coral snakes have complete red, yellow and black rings with red touching yellow. Everything else is harmless. Region filters more than anything else: there are no venomous snakes in Maine, Alaska or Hawaii, and one species across most of the Pacific Northwest.

Does a triangular head mean venomous?

No, and it is the most misleading rule in circulation. Water snakes, hognose snakes and gopher snakes all flatten their heads into a triangle when threatened, which is exactly when you are looking at them. Meanwhile the coral snake, the most medically serious venomous snake in the country, has a narrow head no wider than its neck. Use pattern and region instead.

Is the snake in my pond a cottonmouth?

Almost certainly not unless you are in the southeastern coastal plain — there is no cottonmouth west of central Texas or north of Virginia. In their range, cottonmouths swim with the whole body riding on the surface and stand their ground with a white gaping mouth; harmless water snakes swim with only the head above water and flee. Most reported cottonmouths are northern or banded water snakes.

What do I do if I am bitten?

Move away from the snake, call emergency services, keep the person calm with the limb still and at or below heart level, and remove rings and watches before swelling starts. Mark the edge of the swelling with a pen and note the time. Do not cut, suck, ice, tourniquet, or give alcohol or ibuprofen — all of those make the outcome worse. Antivenom is the treatment and it is only in hospital.

Does the red-and-yellow rhyme actually work?

Within the United States, yes. "Red touches yellow, kill a fellow; red touches black, friend of Jack" reliably separates the eastern coral snake from the scarlet kingsnake and scarlet snake. Coral snakes also have a black snout while the mimics have a red one. The rhyme fails completely in Central and South America, where coral snakes occur in patterns it does not describe.

Do snakes chase people?

No. What people experience as a chase is almost always a snake heading for cover with a person standing between it and that cover. Step to one side and it will pass. Cottonmouths and gopher snakes both hold their ground rather than fleeing, which reads as aggression and is actually a bluff.

What keeps snakes out of a yard?

Removing food and shelter. Secure feed and bird seed, use a closed compost bin, raise woodpiles off the ground, clear plywood sheets and rock piles, cut long grass near the house and seal any gap a mouse could use. Repellents do not work: mothballs, sulphur, lime and ultrasonic devices have all been tested and failed, and mothballs used outdoors are illegal under their own label in the US and poison children and pets.

## Still not sure? Point a camera at it

A filter narrows snakes down to a shortlist. Orvik reads the photo itself and names the species, with the look-alikes ranked underneath so you can check the call yourself.

- [Get Orvik free](https://orvik.app/app/)

## Keep reading on Orvik

- [Identify a snake by picture](https://orvik.app/animals/identify-snake-by-picture/)

- [Snake identification apps](https://orvik.app/animals/snake-identification-app/)

- [Identify an animal by picture](https://orvik.app/animals/identify-animal-by-picture/)

- [Frog vs toad](https://orvik.app/animals/frog-vs-toad/)

- [Animal track identification](https://orvik.app/animals/animal-track-identification/)

- [What type of spider is this?](https://orvik.app/insects/what-type-of-spider-is-this/)

- [What animal makes noise at night?](https://orvik.app/animals/what-animal-makes-noise-at-night/)

## Other free Orvik tools

- [What animal made this track?](https://orvik.app/tools/animal-track-identifier/)
- [Whose droppings are these?](https://orvik.app/tools/animal-scat-identifier/)
- [How old is my dog or cat in human years?](https://orvik.app/tools/pet-age-calculator/)
- [Whose egg is this?](https://orvik.app/tools/bird-egg-identifier/)
- [Which bird did this feather come from?](https://orvik.app/tools/feather-identifier/)
- [What kind of rock is this?](https://orvik.app/tools/rock-identifier/)
- [Which mineral is this?](https://orvik.app/tools/mineral-identifier/)
- [What gemstone is this?](https://orvik.app/tools/gemstone-identifier/)

## Where the data comes from

- [CDC — venomous snakes and first aid](https://www.cdc.gov/niosh/topics/snakes/)
- [American College of Medical Toxicology — snakebite management](https://www.acmt.net/)
- [Amphibians and Reptiles of North America — species accounts](https://amphibiaweb.org/)
- [US Fish and Wildlife Service — protected reptile species](https://www.fws.gov/species)
- [GBIF — Global Biodiversity Information Facility](https://www.gbif.org/)
- [iNaturalist](https://www.inaturalist.org/)

---

HTML version: https://orvik.app/tools/snake-identifier/
Structured data for this site: https://orvik.app/api/v1/openapi.json · https://orvik.app/llms.txt
Free to quote and reuse with a link back to the source URL above (CC BY 4.0).