Pacific rattlesnake (Crotalus oreganus) in Utah in 2019. Credit: Don F Becker, Public Domain (CC0 1.0) Pacific rattlesnake (Crotalus oreganus) in Utah in 2019. Credit: Don F Becker, Public Domain ...

5. Washington. There are around dozen snake species in Washington, all of them being non-poisonous except the northern pacific rattlesnake (Crotalus oreganus oreganus).