The White-tailed jackrabbit’s summer pelt is brownish with some black and tends to appear grayish, it turns white in the winter. The ears are black-tipped, even when the species turns white in winter. The tail is white but occasionally has a dark streak dorsally. It is the largest rabbit in Idaho, being 22 to 26 inches (550-655 mm) total length. This jackrabbit is capable of bursts of speed up to 40 mph with intermittent high and long leaps. It has been recorded jumping higher than 12 feet. The ears and feet of this species are smaller than the black-tailed jackrabbit (ears 3.8 to 4.5 inches; hind feet 5.8 to 6.9 inches). They weigh 6.6 to 13 pounds (3 to 6 kg).
Primarily in Great Basin and northern Great Plains, from Sierra Nevada east to Mississippi River, and from central Canada south to northern New Mexico.
Found in open grasslands and montane shrublands generally above shrub steppe . At higher elevations, found in open areas in pine forests and in alpine tundra . Prefers grass and scattered shrub between sagebrush and mountain forest zones, and is attracted to aspen and fir groves.
In summer, eats grasses, forbs , and grains; may feed on cultivated crops. In winter, browses on twigs, buds, and bark. It seems to be attracted to roadsides after dark to feed on green, succulent vegetation that results from rainfall runoff from the road surface.
Active throughout year. Generally solitary but sometimes aggregates. Primarily crepuscular ; active in early morning and late afternoon and evening (one source reported nocturnal activity period). Rests by day, usually in shallow depressions (form) at base of bush, or beside or in cavity in snow. Occupies greatest range of any jackrabbit. Home range is about 2-3 km in diameter. Populations are known to fluctuate as drastically as with snowshoe hare. Usual population density is generally 2-15/km2, but up to 71 (Iowa) and 43 (Minnesota) per km2 have been reported. Reduction in Northwest populations has been due to overgrazing and agricultural development. They are preyed on by many predators which seems typical of all lagomorphs. There are occasional battles between males, which never seem to result in injury. Kicking with the hind feet while leaping over an opponent seems to be their offensive maneuver.
Breeds from late February to mid-July in North Dakota, from May-early July in northern range. Female produces up to 4 litters/yr (1 litter in northern range) of 1-11 young. gestation lasts 5-6 wk. Young become independent in about 2 months.