Perognathus mollipilosus is a small rodent of arid parts of the western United States. The Wyoming species account records it in open shrublands and shrub-grassland.
The dorsal fur is buff with intermixed black hairs; the underside ranges from buff to whitish.
It is nocturnal and has been recorded in dry sagebrush and greasewood shrubland. The species account also reports carrying seeds to store in burrows.
An extinction-risk assessment has not been added yet.