Tundra Voles have the northernmost distribution of any North American species of Microtus. They are widespread in northern latitudes in Eurasia, too, where they are known as Root Voles, and probably migrated to North America across the Bering land-bridge during the Pleistocene. Learn more about the Microtus oeconomus, more commonly known as a Tundra Vole, in this easy-to-read species overview by the Smithsonian's National Museum of Natural History.