Kangaroo rats (Dipodomys spp.) use a specialized bipedal hopping locomotion like that of kangaroos. In contrast to kangaroos that have elastic tendons capable of storing energy, kangaroo rats have inelastic tendons that are unable to store large amounts of energy. Thus, it is the musculature of the ankle joint that provides the greatest power contribution to hopping. Skeletal muscle can be divided into slow twitch (type I) and fast twitch (type II) fibers. Fast fibers are found in higher percentages in muscles that perform quick, dynamic movements, whereas slow fibers are found in higher proportions in muscles that perform slow, endurant movements. Using fiber type-specific antibodies, we identified four pure (type I, IIA, IIB, and IIX) and two hybrid fiber types (type I/IIA and IIA/IIX) in six hindlimb muscles (Mm. soleus, plantaris, gastrocnemius, tibialis anterior & extensor digitorum longus) from three kangaroo rats (Dipodomys merriami). Soleus was dominated by type I fibers, which are well-known for having a postural role. The other hindlimb muscles studied were dominated by type IIB fibers, which are known to be best suited for rapid and explosive movements. The high percentage of type IIB fibers found in these muscles can be related to the explosive hopping behavior that the kangaroo rat exhibits in order to escape predators, such as rattlesnakes. Oxidative type IIA and type IIX fibers were found at moderate percentages and are suggested to maintain continual saltatory locomotion. Two hybrid fibers (type I/IIA and IIA/IIX) were observed in minimal quantities suggesting that there is limited muscle fiber transformation occurring. By having a heterogeneous muscle fiber type composition, the kangaroo rat can maximize muscle function to display a broad range of force generation and fatigue resistance. properties.