On the west coast of North America, biologists defined the distinctive ring-like distribution of the salamander Ensatina as a "ring species." These salamanders occur along the Pacific coast and their distribution wraps around and through the Sierra Nevada. There are not known populations in between the coast and the mountains; the range forms a ring around areas like California's Central Valley. This is Ensatina eschscholtzii platensis, photographed in the Sierra Nevada foothills of California. These salamanders are found beneath rotting logs and damp leaf litter.