Colorado Snakes: Identification Guide With Pictures

Habitat: Dry plains grassland and sandhill areas; attracted to sandy soils supporting abundant rodent and lizard populations; hibernates singly in rodent burrows, often in firm, loamy soils adjacent to sandy areas used for feeding. (Colorado Parks and Wildlife)

Venom: “Western Rattlesnake (Midget Faded Rattlesnake)*” (Colorado Parks and Wildlife)

Habitat: Virtually every terrestrial habitat within the geographic and elevational range; sandhills, semidesert shrubland, mountain shrubland, riparian zones, pinyon-juniper woodland, and montane woodland; soils may be sandy to rocky; absent from perennially wet areas and high mountains; basically terrestrial, but sometimes climbs into vegetation or onto rocks or logs. Takes shelter in crevices, woodpiles, brushy vegetation, or mammal burrows. Hibernates in rodent burrows or in crevices in rock outcrops. (Colorado Parks and Wildlife)

Range: Found throughout most of Colorado, except the high mountains, reaching an upper elevational limit of 7,500–9,500 feet in different areas of the state. Fairly common in many areas.

Habitat: Virtually every terrestrial habitat within the broad geographic and elevational range; plains grassland, sandhills, semidesert shrubland, mountain shrubland, riparian zones, pinyon-juniper woodland, and montane woodland; soils may be sandy to rocky; absent from perennially wet areas and high mountains; basically terrestrial, but sometimes climbs into vegetation or onto rocks or logs. Takes shelter in crevices, woodpiles, brushy vegetation, or mammal burrows. Hibernates in rodent burrows or in crevice s in rock outcrops. (Colorado Parks and Wildlife)

Venom: “Like all garter snakes, they are mildly venomous, but are not considered dangerous to humans.” (Colorado Parks and Wildlife)

Range: Known to occur as far north as the Arkansas River valley in southeastern Colorado, in John Brown Canyon in Mesa County in west-central Colorado, and in southern La Plata and Archuleta counties in southwestern Colorado, at elevations below 6,500 feet. Spotty distribution, uncommon.

Habitat: Vicinity o f permanent and intermittent streams, often in canyon bottoms with rocky slopes covered in oak and/or juniper; frequently wanders away from streams, sometimes observed in open grassland, especially near dry washes or at temporary pools used by breeding toads. Takes shelters under rocks or wood, in crevices or burrows, or among exposed streamside tree roots. (Colorado Parks and Wildlife)

Venom: “Otherwise, both snakes are mildly venomous, exclusively nocturnal, and rarely seen.” (Colorado Parks and Wildlife)

Range: Colorado Distribution: Southeastern Colorado, mostly south of the Arkansas River, and west-central Colorado and southwestern Colorado; occurs at elevations below 6,000 feet in the southeast, below 6,600 feet in west-central Colorado, and up to 7,900 feet at Mesa Verde in southwestern Colorado. Secretive, difficult to find, but not necessarily rare.

Habitat: Rocky slopes and canyons sparsely vegetated with piñon-juniper woodland and/or various shrubs and grasses; occasionally found in flat plains grassland far from rocky slopes; a ground-dwelling species that seems to spend most of the time under rocks, in crevices or in rodent burrows; found beneath rocks mainly during the mild weather of spring, late summer, and fall. (Colorado Parks and Wildlife)

Venom: “The common garter snake is mildly venomous, but its venom is considered non-dangerous to humans.” (Colorado Parks and Wildlife)

Range: Northeastern Colorado along the South Platte River and its tributaries at elevations below 6,000 feet and North Fork Republican River drainage in Yuma County at about 3,500–3,600 feet; widely distributed along the eastern base of the Front Range.

Habitat: Marshes, ponds, and the edges of streams; basically restricted to aquatic, wetland, and riparian habitats along the floodplains of streams; seldom found away from water or at isolated ponds. Active in shallow water and on land adjacent to water. (Colorado Parks and Wildlife)

Venom: “Otherwise, both snakes are mildly venomous, exclusively nocturnal, and rarely seen.” (Colorado Parks and Wildlife)

Range: Colorado Distribution: Southeastern Colorado, mostly south of the Arkansas River, and west-central Colorado and southwestern Colorado; occurs at elevations below 6,000 feet in the southeast, below 6,600 feet in west-central Colorado, and up to 7,900 feet at Mesa Verde in southwestern Colorado. Secretive, difficult to find, but not necessarily rare.

Habitat: Rocky slopes and canyons sparsely vegetated with piñon-juniper woodland and/or various shrubs and grasses; occasionally found in flat plains grassland far from rocky slopes; a ground-dwelling species that seems to spend most of the time under rocks, in crevices or in rodent burrows; found beneath rocks mainly during the mild weather of spring, late summer, and fall. (Colorado Parks and Wildlife)

Venom: “Only known to exist in one area of Colorado, the eastern hognose is a mildly-venomous snake that specializes in eating toads.” (Colorado Parks and Wildlife)

Habitat: Typically found in sandy habitats. (Colorado Parks and Wildlife)

Venom: “While they are venomous, they are considered harmless to humans.” (Colorado Parks and Wildlife)

Range: Known from southeastern Colorado, the Republican River drainage in northeastern Colorado, and the eastern margin of the Front Range. Secretive, usually difficult to find, but locally common.

Habitat: Flat plains grassland, sandhills, mountain foothills, and rocky canyons; sometimes can be found in old rubbish dumps. A terrestrial and fossorial species that during daylight hours can be found beneath rocks, wood, dried cow dung, or other debris; in yucca plants; and in rotting logs near streams. (Colorado Parks and Wildlife)

Venom: “While plains garter snakes are venomous, their venom is non-toxic to humans.” (Colorado Parks and Wildlife)

Habitat: Vicinity of virtually any permanent or semipermanent flowing or nonflowing body of water; typically along shores and shallows of marshy areas but often strays far from water, showing up in residential areas, dry grasslands, and sandhills. Seeks shelter underground or beneath rocks, logs, or similar cover. (Colorado Parks and Wildlife)

Venom: “This snake uses its venom to subdue prey, but it is harmless to humans and mammals.” (Colorado Parks and Wildlife)

Habitat: Plains grassland, especially where abundant surface cover is present, and, more often, canyon bottoms or riparian areas; infrequently seen in the open; usually under flat rocks or wood in canyon bottoms. Sometimes several individuals of various ages and either sex aggregate under a single rock or log, especially in spring. (Colorado Parks and Wildlife)

Venom: “It is a rear-fanged, venomous snake, but is considered harmless to humans due to its small size and venom being specialized to arthropods.” (Colorado Parks and Wildlife)

Habitat: Mouths of large canyons in areas dominated by sandy, rock-laden soils and xerophytic shrubs (greasewood, sagebrush, saltbush); narrow bottoms of deep, rocky canyons near streamside cottonwood trees; rocky, shrubby slopes above creeks; under rocks in piñon-juniper woodland; under trash in dumps. (Colorado Parks and Wildlife)

Venom: “Like all garter snakes, they are mildly venomous, but are not considered dangerous to humans.” (Colorado Parks and Wildlife)

Range: Throughout most of Colorado, excluding most of the plains region in the northeastern quarter of the state, usually at elevations below 11,000 feet but has been found higher. Common.

Habitat: Almost any terrestrial or wetland habitat in the vicinity of virtually any flowing or non-flowing body of water; not restricted to riparian-aquatic environments, frequently occupies terrestrial habitats far from water. Activity takes place on the ground, in water, or in low vegetation. (Colorado Parks and Wildlife)

Venom: “This is a rear-fanged snake that is venomous, but it is considered non-dangerous to humans.” (Colorado Parks and Wildlife)

Habitat: Sandhills, plains grassland, and sandy floodplains, often in the vicinity of, or along the margins of, streams, irrigation ditches, and ponds. Active on the ground surface or underground. Periods of inactivity are spent burrowed in the soil, in mammal burrows, or, less commonly, under rocks or debris. (Colorado Parks and Wildlife)

Venom: “A non-venomous constrictor that is popular in the pet trade, the California kingsnake has a variety of color variations and striped patterns.” (Colorado Parks and Wildlife)

Range: Known from a few locations in southeastern Colorado (north to the vicinity of the Arkansas River) and a few sites in extreme southwestern Colorado (western Montezuma County), at elevations below about 5,200 feet. Generally difficult to find but may be locally fairly common in the very restricted range in Colorado.

Habitat: Generally associated with lowland river valleys. Western Colorado: has been found in a semi-agricultural situation in the broad bottom of a canyon through which a permanent stream flows and in low, hilly semidesert shrubland above the San Juan River. Southeastern Colorado: has been found near irrigated fields on the floodplain of the Arkansas River, in rural residential areas in plains grassland, near stream courses, and in other areas dominated by shortgrass prairie. Most activity occurs on the ground or in rodent burrows. Periods of inactivity are spent in burrows and logs, in or under old buildings, in other underground spaces, or beneath various types of cover. (Colorado Parks and Wildlife)

Range: Southeastern Colorado, generally at elevations below 6,000 fe et but locally up to 7,700 feet, and the Republican River drainage in northeastern Colorado at elevations of about 3,400-4,500 feet. Widespread and fairly common.

Habitat: Flat or hilly shortgrass prairie, including rocky bluffs and outcrops within these areas; sandhills; canyon slopes with scattered piñon pine and juniper; open riparian woodlands; and mosaics of prairie and agricultural land; this often ground-dwelling snake commonly climbs into shrubs or small trees to bask or search for prey. Takes shelter in burrows, crevices, spaces under rocks or wood, and other secluded sites. (Colorado Parks and Wildlife)

Venom: “This non-venomous constrictor feeds mostly on small mammals, amphibians, and other reptiles.” (Colorado Parks and Wildlife)

Habitat: Sandhills and plains grassland, including riparian zones and areas with soft alluvial soils, as well as canyon bottoms and plains with firm soils. Burrows underground or occupies rodent burrows or similar sites; rarely found under objects on the ground. (Colorado Parks and Wildlife)

Venom: “Gophersnakes and bullsnakes are non-venomous and harmless to humans, but they do deter predators by mimicking rattlesnakes' coiling behavior, which can cause them to erroneously be killed by humans thinking they are threats.” (Colorado Parks and Wildlife)

Habitat: Plains grassland, sandhills, riparian areas, marshes, pond and lake edges, stream-margin logjams, rocky canyons, semidesert and mountain shrublands, pinyon-juniper woodlands, ponderosa pine and other montane woodlands, rural and outlying suburban residential areas, and agricultural areas. Most activity takes place on the ground or in burrows, but these capable climbers sometimes ascend high into trees. (Colorado Parks and Wildlife)

Venom: “They are generally calm and are non-venomous.” (Colorado Parks and Wildlife)

Habitat: Closely associated with river valleys, stream courses, and canyon bottoms; inhabits grassland, weedy areas, shrubland, plains shelterbelts, open conifer woodlands, lowland riparian zones, and semi-agricultural and rural residential areas (especially rodent-infested outbuildings) but usually does not venture far from a permanent or intermittent stream or arroyo. Active on the ground, also a good climber in shrubs, trees, rocky crevices, and buildings. Takes shelter in burrows and other secluded locations, including the foundations of old buildings and similar sites. Sometimes found under objects on the ground during daylight hours. (Colorado Parks and Wildlife)

Habitat: Damp sites in flat plains grasslands, canyon bottom grasslands, riparian areas, and grassy vacant lots and gullies in cities. Secretive, ground-dwelling, burrows in loose soil or hides under rocks, wood, dried cattle dung, or debris; prowls in the open at night during moist mild weather. (Colorado Parks and Wildlife)

Venom: “Long-nosed snakes have alternating black and red saddling on a light-colored background and are non-venomous.” (Colorado Parks and Wildlife)

Habitat: Mainly found in grasslands, sandhills, and weedy river valleys. (Colorado Parks and Wildlife)

Venom: “Milksnakes are non-venomous.” (Colorado Parks and Wildlife)

Habitat: This secretive snake can be found in a variety of habitats, including prairie, sandhills, canyons, river valleys, ponderosa pines, and pinon-juniper. (Colorado Parks and Wildlife)

Venom: “This is a fast-moving, highly active, non-venomous snake.” (Colorado Parks and Wildlife)

Habitat: Eastern Colorado (Colorado Parks and Wildlife)

Venom: “A non-venomous, but aggressive, species of snake found in eastern Colorado.” (Colorado Parks and Wildlife)

Habitat: Creeks, rivers, reservoirs, ponds, marshes, flooded meadows, and canals along major drainage systems; rarely found away from the immediate vicinity of water. Usually seen swimming along marsh edges or basking in semi-secluded onshore sites, on log jams in streams, on mats of algae, on clumps of dead cattails, or up to several feet high in woody streamside vegetation; sometimes under rocks or wood at the water’s edge. (Colorado Parks and Wildlife)

Range: Possible Colorado Distribution: Reported without adequate documentation from Dinosaur National Monument, Moffat County, northwestern Colorado. Occurs in the Uinta Mountains in northeastern Utah.

Habitat: Often in forest openings and meadows associated with stream courses in hills and mountains. Secretive, active on the ground but may climb into vegetation; often takes shelter in burrows or under rock or logs. (Colorado Parks and Wildlife)

Habitat: Lush growths of herbaceous and shrubby vegetation along mountain and foothill streams and meadow habitats adjacent to riparian vegetation. In western Colorado, may be common in mountain shrublands far from water. Usually on the ground, sometimes climbs into low vegetation. Takes shelter in burrows, beneath rocks or wood, or in rotting logs. (Colorado Parks and Wildlife)

Venom: “The striped whipsnake is non-venomous.” (Colorado Parks and Wildlife)

Habitat: Semidesert shrubland in broad basins, piñon-juniper woodland and shrubland on mesa tops and rocky slopes, and intermittent stream courses and arroyos in the bottoms of canyons. Active mostly on the ground surface but readily climbs into vegetation. Seeks shelter in burrows or beneath rocks or other cover. (Colorado Parks and Wildlife)

Habitat: Has been found on canyon slopes and bottoms, including areas with piñon pine, junipers, and various shrubs; usually in damp, loose soil among and under rocks; apparently moves deeper underground when the surface soil becomes dry in summer. Rarely seen in the open, but does sometimes crawl on the surface at night. (Colorado Parks and Wildlife)

Venom: “A member of the colubrid family of snakes - the largest group of snakes in the world - the Western Ground Snake is widely distributed and non-venomous.” (Colorado Parks and Wildlife)

Habitat: Fractured shale outcroppings with numerous platelike rocks, hillsides with many scattered flat rocks partially imbedded in the soil, canyon bottoms, and sand blows, all in areas dominated by shortgrass prairie. Usually found, sometimes in groups, under rocks and other objects on the ground during daylight hours; also uses abandoned mammal burrows. (Colorado Parks and Wildlife)