Gray-tailed voles are sympatric with Townsend's vole (M. townsendii), with which they share many similarities. They can be distinguished by appearance, because Townsend's vole has darker colorings, a longer tail, and differences in the structure of the hard palate.
Gray-tailed voles live alongside Townsend's vole (M. townsendii) and share many characteristics with it. These voles can be distinguished visually due to their different appearances: Townsend's vole is darker, has a longer tail, and its hard palate structure differs from that of the gray-tailed vole.