jackrabbit, popular name for several hares of W North America, characterized by very long legs and ears. Jackrabbits are powerful jumpers and fast runners. In normal progress leaps are alternated with running steps; when pursued the hare runs fast and close to the ground. Jackrabbits are found W of the Great Lakes and the Mississippi River, from S Canada to Central America. They are brownish gray above and white below. The white-tailed jackrabbit ( Lepus townsendi ) is the most northerly species and ranges from plains to high mountains. It has an entirely white tail, and its coat turns white or light gray in winter. It averages 20 in. (51 cm) in length, with ears 5 to 6 in. (12.7–15.3 cm) long. It is closely related to the varying hare and the arctic hare. The blacktailed jackrabbit ( L. californicus ) found on the plains and in arid regions from the NW United States to Mexico, is slightly smaller, with longer ears; its tail is black above. The antelope jackrabbit ( L. alleni ) of Mexico and the extreme SW United States is a large, heavy hare with white sides and ears up to 8 in. (20.3 cm) long. It has been known to leap as high as 5 ft (1.5 m) and as far as 22 ft (6.7 m). Jackrabbits are classified in the phylum Chordata, subphylum Vertebrata, class Mammalia, order Lagomorpha, family Leporidae.