Brush rabbits most commonly live in chaparral vegetation, but are also found in oak and conifer habitats. In the San Francisco Bay Area, it was found that the brush rabbit concentrates its activities at the edge of brush and exhibits much less use of grassy areas. It uses the interior brush of the wilderness and it was also found that this may be a better environment for it than the chaparral one. Studies done on the brush rabbit in Oregon also showed that it rarely left the brushy areas it inhabits. Brush may be used more in the drier seasons while grasses are used in the wetter seasons in relation to growth of annual vegetation. Use of habitat also probably is related to the breeding season.
The brush rabbit is a small rabbit with short legs and a short tail. It is dark gray on the sides and back, and pale gray on the belly and the underside of the tail. The whiskers are mostly black, although some have white tips. Adult rabbits measure anywhere from 303 to 369 mm (11.9 to 14.5 inches) in length, and range in weight from 511 to 917 grams (18 to 32 ounces).
It has been noted that numbers of the eastern cottontail were brought west to reproduce and provide a food source for the settlers. The interbreeding of the two species has occurred where the brush rabbit has in parts of Oregon developed the white cottontail although retaining its smaller size.