The Great Basin pocket mouse, Perognathus parvus, occurs in the Great Basin and surrounding areas of the western United States, as well as in part of southwestern Canada. The species is common in Utah, where it occurs in the western and central parts of the state. Preferred habitats include arid grassland, sagebrush, and pinyon-juniper areas with sandy soil.
Great Basin pocket mice eat primarily seeds, but green vegetation and insects are occasionally consumed. Similar to other pocket mouse species, the Great Basin pocket mouse has external fur-lined cheek pouches used for temporary food storage. Long-term seed storage occurs in underground burrows.
The species breeds during the spring and early summer. Gestation lasts about a month; average litter size is four to five young. Females are capable of producing several litters of young in wet years, when ample food is available. Great Basin pocket mice are nocturnal, solitary, and usually inactive from late fall to early spring.