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Are there cottonmouths (water moccasins) in Missouri?

Last checked November 3, 2026 against official sources.

On this page
  1. The answer
  2. Which ones
  3. Where in the US
  4. Lookalikes
  5. Sources

Yes.

MDC: northern cottonmouth, southeastern corner and a spotty distribution in the Ozark Region.

MDC: “Southeastern corner and a spotty distribution in the Ozark Region.” Source

How we answer questions

On Missouri's official list

Northern Cottonmouth
Photo: Geoff Gallice from Gainesville · CC BY 2.0 · Wikimedia Commons

Northern Cottonmouth

Agkistrodon piscivorus

Venomous per MDC

Danger to people
“The cottonmouth is a dangerously venomous species that can deliver a fatal bite.” MDC
Size
Typically 30 to 48 inches (about 3 to 4 feet); recorded up to 75 inches.
How to recognize it
  • Heat-sensing pit between nostril and eye; no rattle
  • Head much wider than the neck, with a dark bar from the eye to the jaw; vertical (cat-eye) pupils
  • Gapes to show the white lining of its mouth when threatened
Where in Missouri
Southeastern corner and a spotty distribution in the Ozark Region. MDC
65 records by month.
What the sources say

Venom: “There are only six species of venomous snakes in all of Missouri, and they are described in a separate section of this pamphlet.” (MDC)

Habitat: In Missouri, the northern cottonmouth occurs in two distinct habitats. (MDC)

Full Northern Cottonmouth guide

All snakes in the state: Missouri snakes.

Where the cottonmouth lives in the US

Texas: on the state's official listKentucky: on the state's official listGeorgia: on the state's official listMissouri: on the state's official listVirginia: on the state's official listTennessee: on the state's official listLouisiana: on the state's official listFlorida: on an official sourceIllinois: on the state's official listArkansas: on the state's official listMississippi: on the state's official listNorth Carolina: on the state's official listOklahoma: on the state's official listIndiana: on the state's official listSouth Carolina: on the state's official listAlabama: on the state's official listKansas: on the state's official list
Official presence. 17 states where a state list or official source names it. Gray means no official record in our data, not that it is absent.
  • Native or listed
  • Nonnative or not established
  • No official record in our data
Texas: 534 recordsKentucky: 10 recordsGeorgia: 46 recordsMissouri: 65 recordsVirginia: 45 recordsTennessee: 127 recordsLouisiana: 218 recordsFlorida: 16 recordsIllinois: 251 recordsArkansas: 80 recordsMississippi: 88 recordsNorth Carolina: 105 recordsOklahoma: 19 recordsSouth Carolina: 60 recordsAlabama: 90 records
Observation records. Open-licence records on GBIF in 15 states. Records are sightings people shared, not confirmation that a population lives there.
  • 1–9
  • 10–99
  • 100–999
  • 1,000+

Cottonmouth: identification, range and danger

What else it could be

  • Watersnakes

    Seen from directly above, a watersnake's eyes are visible but a cottonmouth's are not. Watersnakes have round pupils and no facial pit, and they usually have thin dark vertical lines on the lips.

  • Diamond-backed Watersnake
    Photo: Peter Paplanus from St. Louis, Missouri · CC BY 2.0 · Wikimedia Commons

    Diamond-backed Watersnake

    Alabama DCNR says this snake is often confused with the cottonmouth. TWRA: the diamond-backed watersnake is lighter, with a chain-like pattern; watersnakes in general lack the cottonmouth's facial pits (see the watersnake entry above).

  • Copperhead
    Photo: USFWSmidwest · Public domain · Wikimedia Commons

    Copperhead

    On young cottonmouths the dark crossbands have many dark spots and speckles; copperhead bands have none or one. Adult copperheads keep the banded pattern, while adult cottonmouths are usually plain and dark. A cottonmouth's eye is hidden in a dark facial band; a copperhead's is not.

When snakes are seen in Missouri

1,154 records (GBIF, CC0 and CC BY).

Other questions about Missouri

Sources

  1. A Guide to Missouri's Snakes (MDC publication E00448). Missouri Department of Conservation (MDC). Copyright 2017; checked November 3, 2026.
    Quoted passages (2)
    “Southeastern corner and a spotty distribution in the Ozark Region.”
    “There are only six species of venomous snakes in all of Missouri, and they are described in a separate section of this pamphlet.”
  2. MDC Field Guide: Reptiles and Amphibians > Snakes (species accounts). Missouri Department of Conservation (MDC). undated page; checked November 3, 2026.
    Quoted passages (1)
    “The cottonmouth is a dangerously venomous species that can deliver a fatal bite.”
  3. GBIF.org occurrence records, human observations licensed CC0 1.0 or CC BY 4.0 only, accessed November 3, 2026. The datasets behind these counts are listed on our Sources page.