This small mouse lives in mountain forests of Oaxaca in southern Mexico. Dark fur on its wrists and lower forelegs stands out; it forages at night for seeds and other foods on the forest floor.
Its back is grayish brown and its underside is white. The wrists and lower forelegs are much darker than the surrounding fur.
It is active at night and searches the forest understory for seeds, fruit, fungi, and invertebrates. Shallow burrows beneath roots, logs, or rocks are also reported.
Year-round breeding is common among Mexican cloud-forest Peromyscus, including this species; breeding intensity may peak at the start of the wet season.
An extinction-risk assessment has not been added yet.