Peromyscus furvus Allen and Chapman, 1897 is a cricetid rodent commonly called the blackish deermouse because of its characteristically dark pelage coloration. It is 1 of 56 species in the genus Peromyscus and is of large size compared with the majority of its congeners. Its distribution is restricted to moderate- to high-elevation cloud forests along the eastern slopes of the Sierra Madre Oriental in Mexico. The International Union for Conservation of Nature and Natural Resources' status was recently reassessed and set to “Data Deficient,” although P. furvus has lost the majority of its natural habitat to deforestation. Sequence data indicate that P. furvus may be a composite taxon, with the southern population forming an independent evolutionary lineage.