The range of Western Pond Turtle habitat in Oregon

 The Western Pond Turtle is native to the Pacific Coast of the United States. Its historical range is from the Puget Sound area in Washington to Baja California, extending into Canada. There are two sub-species of the Western Pond Turtle: the Southwestern Pond Turtle (Clemmys marmorata pallida) which occurs from Monterey Bay southward, and the Northwestern Pond Turtle (Clemmys marmorata marmorata) found north of the Sacramento Valley. While the Western Pond Turtle still inhabits the same historical range, their population within the range has declined dramatically. The population of the Western Pond Turtle is difficult to estimate due to the lack of accurate tracking methods and devices used to locate nesting sites.

The largest populations are scattered from southern Oregon to California where they are well adapted to the arid climate. The species is uncommon in the rest of its range. There are roughly 448 known locations of the WPT in the Willamette River Basins, 210 (47%) are located on public lands. There are many more locations on private lands that are unaccounted for. Some 59 (13%) of the 448 known locations of the WPT in the Willamette River Basin are based in the Long Tom watershed in the Eugene area. The foothills of the Lower Willamette River basin are providing the best habitat in Oregon. Because the turtles spend much of their lives in water but nest on land, the turtles require an environment with both meadows and ponds that is relatively free of human disturbance. This makes it difficult because the Willamette Valley not only has the best habitat for turtle but it is the heaviest human populated region of the state. More than 92 percent of Columbia River Gorge habitat has been altered and isolated by development resulting in a sharp decline in pond turtle.