Month by month

What Reptiles and Amphibians Are Out in Colorado in April

38 reptiles and amphibians are active in Colorado in April, and 27 are at peak. Peak species include the Western Terrestrial Garter Snake, Gopher Snake, Prairie Lizard, and American Bullfrog.

Counted from iNaturalist research-grade observations recorded inside Colorado. Seasons shift across the state, so for a closer match, pick your ecoregion.

Full 12-month Colorado calendar Pick your ecoregion

Species out across Colorado, by group and month

Group
Snakes			5	15	17	17	16	16	14	11	5	1
Lizards		2	6	12	13	13	13	13	12	7	3
Turtles		2	3	5	5	5	5	5	5	4	3
Frogs and Toads	1	1	3	5	9	9	9	9	8	5	2	1
Salamanders		1	1	1	1	1	1	1	1	1	1	1

Numbers = species active that month (at peak or just starting / winding down).

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At peak in April 27

Snakes

peak

SnakesCommon Garter SnakeThamnophis sirtalis

peak

SnakesCommon WatersnakeNerodia sipedon

peak

SnakesGopher SnakePituophis catenifer

peak

SnakesGreat Plains Ground SnakeSonora episcopa

peak

SnakesGreat Plains RatsnakePantherophis emoryi

peak

SnakesNorth American RacerColuber constrictor

peak

SnakesPlains Black-headed SnakeTantilla nigriceps

peak

SnakesPlains Garter SnakeThamnophis radix

peak

SnakesStriped WhipsnakeMasticophis taeniatus

peak

SnakesWestern MilksnakeLampropeltis gentilis

peak

SnakesWestern Terrestrial Garter SnakeThamnophis elegans

Lizards

peak

LizardsCommon Sagebrush LizardSceloporus graciosus

peak

LizardsCommon Side-blotched LizardUta stansburiana

peak

LizardsEastern Collared LizardCrotaphytus collaris

peak

LizardsGreater Short-horned LizardPhrynosoma hernandesi

peak

LizardsOrnate Tree LizardUrosaurus ornatus

peak

LizardsPlateau Fence LizardSceloporus tristichus

peak

LizardsPrairie LizardSceloporus consobrinus

peak

LizardsWestern Earless LizardHolbrookia maculata

peak

LizardsWestern WhiptailAspidoscelis tigris

Turtles

peak

TurtlesCommon Snapping TurtleChelydra serpentina

peak

TurtlesPainted TurtleChrysemys picta

peak

TurtlesPond SliderTrachemys scripta

introduced

peak

TurtlesSpiny SoftshellApalone spinifera

Frogs and Toads

peak

Frogs and ToadsAmerican BullfrogLithobates catesbeianus

peak

Frogs and ToadsBoreal Chorus FrogPseudacris maculata

Salamanders

peak

SalamandersWestern Tiger SalamanderAmbystoma mavortium

Shoulder season in April 11

Snakes

shoulder

SnakesCommon CoachwhipMasticophis flagellum

shoulder

SnakesLined SnakeTropidoclonion lineatum

shoulder

SnakesPrairie RattlesnakeCrotalus viridis

venomous

shoulder

SnakesSmooth GreensnakeOpheodrys vernalis

Lizards

shoulder

LizardsPlateau Striped WhiptailAspidoscelis velox

shoulder

LizardsSix-lined RacerunnerAspidoscelis sexlineatus

shoulder

LizardsTexas Horned LizardPhrynosoma cornutum

Turtles

shoulder

TurtlesOrnate Box TurtleTerrapene ornata

Frogs and Toads

shoulder

Frogs and ToadsNorthern Leopard FrogLithobates pipiens

shoulder

Frogs and ToadsPlains Leopard FrogLithobates blairi

shoulder

Frogs and ToadsWoodhouse's ToadAnaxyrus woodhousii

Peak and shoulder ratings are rough guidance, not a schedule. Weather, elevation and the year can shift any species by weeks.

Rare and protected species are left off on purpose. Look, don't take, and never handle a venomous snake.

Colorado in April

What reptiles and amphibians are out in Colorado in April?

38 reptiles and amphibians are active in Colorado in April, and 27 are at peak. Peak species include the Western Terrestrial Garter Snake, Gopher Snake, Prairie Lizard, and American Bullfrog.

Are venomous snakes active in Colorado in April?

Yes. The Prairie Rattlesnake can be active in April. Watch where you step and don't handle them.