Few people realize that reptiles do occur naturally in Alaska because they forget to include non-breeding populations of marine turtles that venture into the state's waters. Four species, all federally protected under the Endangered Species Act, can be found from time to time in coastal waters including Leatherback Sea Turtles, Green Sea Turtles, Olive Ridley Sea Turtles and Loggerhead Sea Turtles.
Only the Leatherback is suspected to be able to survive the cold northern waters of Alaska and most other turtle visitors succumb to hypothermia in the fall. Turtle remains and shells are found periodically along Alaska's shores, and this is probably only a fraction of the animals that have ended up in the state. Until recently, Bruce Wing - curator of the Auke Bay Laboratory of the National Oceanic and Atmospheric Administration (NOAA) in Juneau - had been keeping detailed records of sea turtle sightings across Alaska. Wing retired from federal service and in 2013, the laboratory closed along with the dedicated effort to track Alaska's sea turtles. AHS is attempting to continue these efforts!
While there are no confirmed native populations of snakes in Alaska, several credible reports of garter snakes have been made over the years that may be valid accounts of natural movements into the state. Three species of garter snake occur naturally in British Columbia. The drier warmer climates on the other side of the coastal mountains provide much better habitat for these species. The reports have often been from three of southeast Alaska's major drainages that provide corridors through the mountains to the coast: the Taku, the Stikine, and the Unuk Rivers. What we think may be happening is that major upriver flooding events periodically push snakes to the coast but they have thus far failed to establish populations and / or overwinter successfully.
Several garter snakes have been found across Alaska that are suspected to be pets or animals that traveled with cargo to the state. You can read more about these snake encounters by visiting our INTRODUCED SPECIES page.