Northern desert nightsnake (Hypsiglena chlorophaea deserticola)

Category: Reptiles
Family: Colubridae
Common names: Great Basin night snake
Ecosystems: Shrubsteppe
Vulnerability to climate change (More details)


If you see this species, please share your observation using the WDFW wildlife reporting form. Providing detailed information such as a photo and exact coordinates will improve the confidence and value of this observation to WDFW species conservation and management.

This small snake is found in the Columbia Basin in Washington. It is of conservation concern in the state based on its rarity and because it primarily occurs in shrubsteppe habitat, which is declining.

Most shrubsteppe habitat in Washington has been converted to other uses or degraded by frequent fires and invasive weeds. Loss of this habitat is predicted to continue.

Description and Range

Physical description

Nightsnakes resemble western rattlesnakes, but do not have a rattle or a “button” (single rattle) on the tail like a rattlesnake. The nighsnake is a small (less than 18 inches in total length), spotted snake with a small head and mouth. They have dark brown blotches in the neck region, smooth scales, and vertical pupils. This species has a dark eye stripe from the nostril to the jaw. The upper labial scales are white speckled with brown. The ventral (underside) scales have a “pearly” white sheen and no markings.

The nightsnake’s fangs are in the back of the mouth (“rear-fanged”) and the venom is “chewed” into the wound of their prey. This is unlike a rattlesnake that has long fangs at the front of the mouth that inject venom into prey.

In addition to a resemblance to western rattlesnake, other Washington species that are similar in appearance include the gopher snake and juvenile racer. Only the northern desert nightsnake has both smooth scales and vertical pupils

For more details about this desert nightsnake, see the Washington Herp Atlas

Ecology and life history

Most nightsnake occurrences in Washington are from arid areas that support shrubsteppe vegetation, but occurrences in the Leavenworth area are in ponderosa pine forests. Individuals are usually found in rocky areas, but have also been found in sagebrush flats that are not rocky. During the day, individuals can be found sheltering under surface objects, generally rocks. However, during prolonged periods of hot weather, they may move deep into talus, rock fissures or rodent burrows.

As their common name suggests, they are primarily active at night (i.e., nocturnal).

In Washington, these snakes are active from April to October. Mating takes place in the spring. Three to nine eggs are laid in June or July each year. 

Nightsnakes eat small lizards and smaller snakes, as well as lizard eggs, frogs, and other small prey.

Geographic range

In Washington, northern desert nightsnakes have been documented in the Columbia Plateau, Eastern Cascades, and Okanogan Ecoregions. Distribution may be limited by the occurrence of certain lizard prey species. From 2003 to 2004, 66 new observations were made from seven Washington counties by a student as part of his graduate studies at Central Washington University. This provided the evidence that the species was more common than was previously known.

This map from the Washington Herp Atlas illustrates the distribution of northern desert nightsnake in Washington based on records in the WDFW database as of 2016. If you see this species in areas that are not indicated on the map or have more recent observations (less than 10 years), please share your observation using the WDFW wildlife reporting form

Northern desert nightsnake detection map:all eastside counties except Ferry,Stevens,Pend Oreille,Spokane,Whitman,Adams,Asotin
Washington Herp Atlas (2017)

For a map of range-wide distribution and conservation status of this species, check out NatureServe Explorer.

Climate vulnerability

Sensitivity to climate change


Northern desert nightsnake, a small egg-laying largely nocturnal snake that tends to be associated with rocky habitats but has a highly relatively plastic diet though it may take reptiles more frequently, seems relatively robust to historical changes in climate. If any particular sensitivity to climate change exist, it may be linked to dietary specialization of local populations. Uncertainty exist with regard to the impact of climate change on overwintering and oviposition sites, but neither is anticipated to be create particularly great vulnerabilities for this species. Altered fire regimes and invasive weeds have an uncertain likelihood of affecting northern desert nightsnakes.  

Confidence: Moderate

Exposure to climate change


  • Altered fire regimes
  • Increased invasive weeds
  • Temperature changes may affect diet of local populations
Confidence: Moderate


Licenses and permits

Be advised that collection of this species is only permitted under a WDFW Scientific Collection Permit for research and educational activities.


This species is identified as a Species of Greatest Conservation Need (SGCN) under the State Wildlife Action Plan (SWAP). SGCN-classified species include both those with and without legal protection status under the Federal or State Endangered Species programs, as well as game species with low populations. The WDFW SWAP is part of a nationwide effort by all 50 states and five U.S. territories to develop conservation action plans for fish, wildlife and their natural habitats—identifying opportunities for species' recovery before they are imperiled and more limited.

Conservation Threats and Actions Needed

  • Resource information collection needs
    • Threat: Lack of information
    • Action Needed: Research, survey and monitoring are needed to understand the status, distribution and habitat needs of this species.
  • Fish and wildlife habitat loss and degradation
    • Threat: Loss and degradation of suitable shrubsteppe habitat that this species relies upon in Washington.
    • Action Needed: A strategy needs to be developed to make sure enough suitable shrubsteppe habitat is maintained to support viable populations of this snake.
  • Overharvesting of biological resources
    • Threat: Destruction of rattlesnake hibernacula also negatively affects night snakes because they often share hibernacula with rattlesnakes.
    • Action Needed: Environmental education and outreach. Protect snake dens on public lands.

See the Climate vulnerability section for information about the threats posed by climate change to this species.

Living with wildlife

Snakes are among the most misunderstood of all animals. Of the dozen or so species of snakes found in Washington, only the western rattlesnake is capable of inflicting a venomous bite, which it seldom does. All snakes are an important part of the natural food chain, eating a variety of prey—from mice and birds to frogs and insects.

Observe snakes, like all wild animals, from a respectful distance. Learn more about living with snakes.



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Leonard, W. P. and M. A. Leonard. 1998. Occurrence of the Sharptail Snake (Contia tenuis) at Trout Lake, Klickitat County, Washington. Northwestern Naturalist 79: 75-76.

Leonard, W.P. and K. Ovaska. 1998. Contia, C. tenuis. Catalogue of American Amphibians and Reptiles: 677.1-677.7. 

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Storm, R. M. and W. P. Leonard (Coordinating Editors). 1995. Reptiles of Washington and Oregon. Seattle Audubon Society, The Trailside Series, Seattle, Washington. 176 pp.

Weaver, R. E. 2008. Distribution, abundance, and habitat associations of the Night Snake (Hypsiglena torquata) in Washington State. Northwestern Naturalist 89: 164-170.

Zweifel, R.G. 1954. Adaptation to feeding in the snake Contia tenuis. Copeia 1954(4): 299-300.

Personal communications

William (Bill) Leonard, Washington Department of Transportation, Olympia, Washington.

Robert Weaver, Graduate Student, Central Washington University, Ellensburg, Washington.

WDFW publications

WDFW educational resources

Other resources