This large deer mouse lives in the highland forests of Oaxaca, with a dark back, ocher sides, and a slate-gray belly. It uses the dense understory of high-elevation forest.
The back has thick dark-brown fur, while the sides are ocherous. The belly is slate gray and may include black-tipped hairs.
It has been recorded at 2,400–3,500 m in cloud forest and pine-oak forest, in areas thick with vines and shrubs. Vegetation and berries have been reported from stomach contents.
An extinction-risk assessment has not been added yet.