The Northern grasshopper mouse is a stockily built mouse with a thick tail. The dorsal pelage is dark sepia long the midline grading moderately sharply to a light tannish along the sides. The ventral pelage is white. A dark sepia line extends across the face between the eyes. The ears are thinly furred, sepia on the external surface and light grayish-tan on the internal surface. The feet and tip of the tail are white.
In Oregon, Northern grasshopper mice have been found in grassland and desert areas in Crook, Deschutes, Gilliam, Harney, Jefferson, Klamath, Lake , Malheur, Morrow, Sherman, Umatilla, and Wheeler counties.
These mice are strongly nocturnal, with peak activity at the new moon and minimum activity at the full moon. Light rain produces an increase in activity and heavy rain suppresses activity.