The long-tailed vole (Microtus longicaudus), in some areas known as the San Bernardino long-tailed vole, is a small vole found in western North America. They have short ears and a long tail. Their fur is gray brown with light gray underparts. They are around 18 cm (7.1 in) long with an 8 cm (3.1 in) tail and weigh about 50 g (1.8 oz).