The San Bernardino kangaroo rat follows the same body plan as Dipodomys merriami and other kangaroo rat species: large hind feet for jumping, long tail for balance while jumping, cheek pouches for foraging, and so on.
D. m. parvus is substantially darker and smaller than the other two D. merriami subspecies that live in Southern California (Dipodomys merriami merriami and Dipodomys merriami collinus).