Washington State does have a native venomous snake, though it is confined to specific regions of the state. The species is the Western Rattlesnake, scientifically known as Crotalus oreganus, which is the single species of pit viper found within Washington’s borders. Recognizing the presence of this snake and understanding its habits is important for anyone recreating in the state’s dry, eastern landscapes. While bites are rare, being informed about this animal is the most effective way to ensure safety.
The Sole Venomous Resident
The Western Rattlesnake is Washington’s only resident snake that possesses medically significant venom. This species belongs to the pit viper family, characterized by heat-sensing pits located between the eye and the nostril, which aid in locating warm-blooded prey. While they can reach lengths of up to 5 feet, most individuals encountered are around 36 inches long.
The venom is complex, but its effects are primarily hemotoxic, meaning it targets and breaks down blood cells and surrounding tissue. This composition contains metalloproteinases and other enzymes that cause severe localized pain, swelling, and tissue damage at the bite site. Rattlesnakes are secretive and not aggressive, preferring to avoid confrontations and will only strike when they feel threatened or provoked.
They rely on their venom mainly for subduing and digesting prey, which consists mostly of rodents and other small mammals. Juvenile rattlesnakes are born with fully functional venom, and while they inject less volume than adults, their venom composition can sometimes be more potent. The primary defense mechanism is the distinctive rattle, which serves as an auditory warning.
Identifying Features and Geographic Range
The geographic distribution of the Western Rattlesnake is restricted to the arid and semi-arid regions of Central and Eastern Washington, generally east of the Cascade Mountain range. They thrive in the shrubsteppe ecosystem, often found in rocky areas, talus slopes, grasslands, and brushy canyons where they find suitable dens for overwintering.
Visually distinguishing the Western Rattlesnake from non-venomous species is a valuable public safety skill. They possess a broad, triangular head that is noticeably wider than their neck, a trait common to pit vipers due to the location of their venom glands. Their bodies are stout and heavy, typically covered in a pattern of dark, often greenish-brown or gray blotches along their back.
The most defining feature is the segmented rattle on the tail, though young snakes may only have a small “button” and cannot produce the characteristic sound. This rattle is often confused with the tail-vibrating behavior of the non-venomous Gopher Snake, a common mimic in the same regions. Unlike the rattlesnake, the Gopher Snake has a more rounded head, round pupils, and a more slender body that tapers gradually to a thin tail.
Prevention and Emergency Protocol
Avoiding rattlesnake encounters relies on awareness of their habitat and activity patterns. When hiking in Eastern Washington during warmer months, wear over-the-ankle boots and long pants. Stay on established trails and never place hands or feet where they cannot see, such as under rocks, logs, or thick brush.
If a rattlesnake is encountered, slowly and calmly back away to a safe distance. Should a bite occur, remain calm and immediately call 911 or emergency medical services. Keep the bitten limb still and positioned at or below the level of the heart to slow the spread of venom.
Remove all jewelry or constricting items near the bite immediately, as swelling is rapid. Avoid harmful first-aid measures:
- Do not apply a tourniquet.
- Do not cut the wound.
- Do not attempt to suck out the venom.
- Do not apply ice.
The only effective treatment for a significant bite is antivenom administered by medical professionals in a hospital setting.