Rattlesnakes are present in Oregon, though they are not found uniformly throughout the state. As the only dangerously venomous reptile species in Oregon, encounters are uncommon because the snakes prefer specific habitats and generally avoid human interaction. Understanding their habitat and how to respond to an encounter allows residents and visitors to safely coexist with these native pit vipers.
Identifying the Species Found in Oregon
The only indigenous species of rattlesnake in the Pacific Northwest is the Western Rattlesnake (Crotalus oreganus). This species is divided into two subspecies in Oregon: the Northern Pacific Rattlesnake (Crotalus oreganus oreganus) and the Great Basin Rattlesnake (Crotalus oreganus lutosus). Western Rattlesnakes average 30 to 39 inches in length.
Coloration varies significantly based on the environment, ranging from brown or greenish-brown in forested areas to buff-tan in open deserts. The snakes are characterized by large, dark blotches along their back, a broad, triangular head, and the distinct rattle at the end of their tail. As pit vipers, they possess heat-sensing pits that aid in detecting warm-blooded prey, often becoming crepuscular—most active at dawn and dusk—during summer to avoid midday heat.
Mapping Their Range and Habitat
Rattlesnake distribution is heavily concentrated in the eastern portion of the state, primarily due to climatic and terrain preferences. The Cascade Mountains create a significant barrier, resulting in the vast majority of the population inhabiting the drier environments east of the range. These areas include the high desert, sagebrush steppelands, juniper woodlands, and rocky canyon lands.
The Northern Pacific Rattlesnake subspecies is found across central and northeastern Oregon, occupying pine and juniper woodlands. The Great Basin Rattlesnake is restricted to the arid plains and desert landscapes of southeastern Oregon. While primarily found east of the Cascades, some Northern Pacific populations exist in the valleys and oak habitats of southwestern Oregon, such as the Rogue and Umpqua River areas. Rattlesnakes seek out south-facing rocky slopes and crevices for their communal dens, where they hibernate during the winter months.
Safety and Emergency Response
To prevent a snake bite, be aware of your surroundings when recreating in known rattlesnake territory during their active season from April to October. Wearing sturdy, high-top boots and long pants offers a layer of protection. Watch carefully where you place your hands and feet. Avoid stepping over logs or large rocks without looking first, and never place hands into crevices, holes, or thick brush where a snake may be seeking shelter.
If a bite occurs, it is a medical emergency requiring prompt action. Call 9-1-1 immediately and try to remain calm, as an elevated heart rate can speed the spread of venom. Keep the bitten limb still and positioned at or below the level of the heart, and remove any tight clothing or jewelry near the bite area before swelling begins.
Do not attempt to suck the venom out, cut the wound, apply a tourniquet, or use ice, as these actions are ineffective and can cause further tissue damage or infection. The only effective treatment is antivenom, which must be administered by medical professionals. Note the time of the bite, which will help hospital staff determine the appropriate course of treatment.