This mouse is known from northern Peru at 3,050–3,660 m. Its back is dark gray and its underside paler; records include forest, grassland, and streamside shrubland.
Its fur is long, soft, and dense. The back is dark gray with brownish sides, the belly is paler gray to buff, and the thick tail is nearly as long as the body.
Natural-history specimens were collected in dense humid forest. Later records also include puna grassland, rocky or shrubby ground, streamside shrubs, and montane forest.
An extinction-risk assessment has not been added yet.