The northern rock mouse, Peromyscus nasutus, is a fairly nondescript mouse native to parts of the southwestern United States. In Utah, the northern rock mouse is rare, and its range includes only the southeastern corner of the state.

Northern rock mice eat seeds, fruits, nuts, and insects. The species mates during the spring and early summer. Gestation lasts about four weeks, and females can produce multiple litters of three to four young each year. The northern rock mouse is a nocturnal species that is active year-round. Rocky areas in woodland and shrubby habitats are preferred by the northern rock mouse.