Northern Pacific rattlesnake
The only rattlesnake in these Northern California volcanic parks, born fully venomous but silent, with a single button instead of a working rattle.
Northern Pacific rattlesnake at a glance
Crotalus oreganus Crotalus oreganus is KROT-uh-luss or-EG-uh-nuss
- Type
- Reptile · snake
- Diet
- Carnivore
- Size
- A grown Northern Pacific rattlesnake is usually about 3 feet long, close to the height of a kitchen counter (about 100 centimeters), though the largest on record measured over 5 feet (162.6 centimeters / 64 inches). A newborn is about as long as a new pencil, roughly 10 inches / 25 centimeters.
- Lifespan
- Not firmly established in the sources checked for this page.
- Conservation
- Least concern
Eats mice, voles, ground squirrels, young rabbits, birds, lizards
It waits coiled near a rodent burrow, log, or rock ledge, senses body heat through a pit between each eye and nostril, and strikes fast, then follows the scent trail to wherever the venom brings its prey down.
Should you worry?
This is the only rattlesnake in these parks, and it is venomous, so give it real respect, not panic. It does not hunt people and would rather retreat than bite. Almost every bite happens when someone tries to touch, corner, or kill the snake. Stay on the trail, watch where hands and feet land on sun-warmed rocks and logs, and if a buzzing rattle sounds, stop, find the snake, and back away. Even a newborn, only about 10 inches long, is already fully venomous, so "small" never means "safe." Give it room and it will move off.
Some late-summer nights at Lava Beds or Lassen Volcanic, a female Northern Pacific rattlesnake gives birth on a rock ledge to a litter of live young, each one already coiled and ready. A newborn is about as long as a school ruler, and its tail ends in a single yellow button, not a rattle. Shake it and nothing happens. It won’t buzz until it sheds its skin for the first time and grows a second segment behind that first one.
Silent tail or not, the newborn already hunts like an adult. A rattlesnake finds a meal by heat, not sight. A pit between each eye and nostril reads the warmth of a mouse or vole in the dark, and the strike follows in a fraction of a second. This is the only rattlesnake species at Lassen Volcanic, Lava Beds, and Redwood, a far shorter list than the half-dozen rattlesnake species sharing the desert parks farther south.
None of that makes the snake worth fearing on a trail. It would rather retreat than bite, and almost every bite on record happens when someone tries to touch, corner, or kill one. The one rule that doesn’t bend: a newborn’s venom is already full strength even though its rattle can’t warn anyone yet, so treat every rattlesnake the same, however small. Hear that dry buzz, stop, find the snake, and let it own the rock while you go around.
Did you know?
- A newborn rattlesnake's tail carries a single yellow button that cannot make sound. It takes a first shed before the first true rattle segment is added behind it.
- This is the only rattlesnake species found in Lassen Volcanic, Lava Beds, and Redwood, a much shorter list than the half-dozen rattlesnake species at the desert parks farther south.
- The snake is most active at dawn, dusk, and night in hot weather, but switches to daytime hunting when temperatures are milder.
Common questions
Are Northern Pacific rattlesnakes dangerous to kids?
They are venomous, so treat them with respect, but they do not chase people. Stay on the trail, never touch one, and back away slowly if you hear a rattle.
Can a baby rattlesnake still bite?
Yes. A newborn is already fully venomous even though its tail only carries a silent button, not a working rattle yet.
What should I do if I hear a rattle?
Stop, look for the snake without moving closer, then step back the way you came and go around it with plenty of room.
What do Northern Pacific rattlesnakes eat?
Mostly mice, voles, and ground squirrels, along with birds and lizards, all found using heat-sensing pits on the face.