Western Pond Turtles are currently endemic to the Pacific Coast of the USA. They are often found in small ponds or large creeks, rarely in very large and/or cold rivers.
http://www.californiaherps.com/turtles/pages/a.marmorata.html
http://www.oregonturtles.com/native_turtle
http://www.iucnredlist.org/details/4969/0