Month by month

What Reptiles and Amphibians Are Out in Colorado in May

45 reptiles and amphibians are active in Colorado in May, and 38 are at peak. Peak species include the Western Terrestrial Garter Snake, Woodhouse's Toad, Gopher Snake, and Prairie Lizard.

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 May 38

Snakes

peak

SnakesCommon CoachwhipMasticophis flagellum

peak

SnakesCommon Garter SnakeThamnophis sirtalis

peak

SnakesCommon WatersnakeNerodia sipedon

peak

SnakesGlossy SnakeArizona elegans

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

SnakesPlains Hognose SnakeHeterodon nasicus

peak

SnakesPrairie RattlesnakeCrotalus viridis

venomous

peak

SnakesStriped WhipsnakeMasticophis taeniatus

peak

SnakesWestern MilksnakeLampropeltis gentilis

peak

SnakesWestern Terrestrial Garter SnakeThamnophis elegans

Lizards

peak

LizardsCommon Checkered WhiptailAspidoscelis tesselatus

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

LizardsPlateau Striped WhiptailAspidoscelis velox

peak

LizardsPrairie LizardSceloporus consobrinus

peak

LizardsSix-lined RacerunnerAspidoscelis sexlineatus

peak

LizardsWestern Earless LizardHolbrookia maculata

peak

LizardsWestern WhiptailAspidoscelis tigris

Turtles

peak

TurtlesCommon Snapping TurtleChelydra serpentina

peak

TurtlesOrnate Box TurtleTerrapene ornata

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

peak

Frogs and ToadsPlains SpadefootSpea bombifrons

peak

Frogs and ToadsRed-spotted ToadAnaxyrus punctatus

peak

Frogs and ToadsWoodhouse's ToadAnaxyrus woodhousii

Salamanders

peak

SalamandersWestern Tiger SalamanderAmbystoma mavortium

Shoulder season in May 7

Snakes

shoulder

SnakesLined SnakeTropidoclonion lineatum

shoulder

SnakesSmooth GreensnakeOpheodrys vernalis

Lizards

shoulder

LizardsTexas Horned LizardPhrynosoma cornutum

Frogs and Toads

shoulder

Frogs and ToadsGreat Plains ToadAnaxyrus cognatus

shoulder

Frogs and ToadsMexican SpadefootSpea multiplicata

shoulder

Frogs and ToadsNorthern Leopard FrogLithobates pipiens

shoulder

Frogs and ToadsPlains Leopard FrogLithobates blairi

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 May

What reptiles and amphibians are out in Colorado in May?

45 reptiles and amphibians are active in Colorado in May, and 38 are at peak. Peak species include the Western Terrestrial Garter Snake, Woodhouse's Toad, Gopher Snake, and Prairie Lizard.

Are venomous snakes active in Colorado in May?

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