Are there alligators in Colorado?
Last checked November 3, 2026 against official sources.
On this page
Not established.
USGS NAS lists four nonindigenous alligator records in Colorado (1978, 1991, 2005, 2009), each with status "failed" (not established).
More official answers for Colorado
Are there venomous snakes in Colorado?
Yes. CPW says there are three kinds of rattlesnakes in Colorado (prairie rattlesnake, midget faded/western rattlesnake, massasauga); CPW's Quick Key lists these three as the venomous snakes of Colorado. Colorado Parks and Wildlife
Are there copperheads or cottonmouths in Colorado?
Not on the official list. Neither is in CPW's list of Colorado snakes; CPW names only rattlesnakes as venomous. USGS NAS has one non-native Cottonmouth record (collected 1965, Adams County). USGS Nonindigenous Aquatic Species (NAS) database
Where the American alligator lives in the US
- Native or listed
- Nonnative or not established
- No official record in our data
- 1–9
- 10–99
- 100–999
- 1,000+
Where official sources do confirm it
Official sources confirm the American alligator in 10 states: Alabama, Arkansas, Florida, Georgia, Louisiana, North Carolina, Oklahoma, South Carolina, Tennessee and Texas. Oklahoma borders Colorado.
- Oklahoma: “American alligators are difficult to find in Oklahoma. But they can be found in remote and marshy areas in the southeastern corner of the state.” Oklahoma Department of Wildlife Conservation
What else it could be
Photo: Dennis Vollmar · CC BY 4.0 · iNaturalist American crocodile
Crocodile: lighter grayish-green skin, narrow tapered triangular snout, fourth lower tooth visible with the mouth closed, and mostly coastal brackish or salt water in south Florida. Alligator: darker, broad rounded snout, mostly fresh water.
Photo: Charles J. Sharp · CC BY-SA 4.0 · Wikimedia Commons · resized Spectacled caiman
USGS: the common (spectacled) caiman's snout is not as broad and round as the American alligator's, and unlike the alligator it has a unique bony ridge in front of and between the eyes.
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If you see one in Colorado
Keep your distance and do not try to catch or handle it. Invasive species: file a report with CPW (online "Report a Sighting" form linked from cpw.state.co.us/invasive-wildlife). Injured/abandoned animals, feeding or illegal activity: CPW Denver Headquarters 303-297-1192 or any CPW office; anonymous: Operation Game Thief 877-265-6648. After-hours emergency: Colorado State Patrol 303-239-4500. Wildlife posing immediate danger: local CPW office or law enforcement. Colorado Parks and Wildlife
Other questions about Colorado
Sources
- NAS occurrence API: Alligator mississippiensis in Colorado. USGS Nonindigenous Aquatic Species (NAS) database. live API query 2026-11-03; checked November 3, 2026.
- Crossing Paths with Wildlife. Colorado Parks and Wildlife. page states 2026-01-28T13:29:23-0700; checked November 3, 2026.
Quoted passages (1)
“There are three kinds of rattlesnakes in Colorado.”
- NAS Species List: Reptiles, Colorado. USGS Nonindigenous Aquatic Species (NAS) database. undated page; checked November 3, 2026.
- Known Invasive Wildlife in Colorado. Colorado Parks and Wildlife. page states 2026-01-21T15:12:28-0700; checked November 3, 2026.
Quoted passages (1)
“If you spot any invasive species, file a report with CPW.”