Most widespread kangaroo rat in California. Occurs in desert scrub and alkali desert scrub, sagebrush, Joshua tree, and pinyon-juniper habitats in southern California. Occurs in California from Benton, Mono Co., south to Olancha, Inyo Co., and Onyx, Kern Co., Colton, San Bernardino Co., Aguanga, Riverside Co., Campo, San Diego Co., and in all arid lands east to the Nevada and Arizona borders. Granivorous, feeding opportunistically on the seeds of plants in relation to their availability and abundance. Arthropods are eaten seasonally.
Sandy soils are preferred but rocky flats are utilized, provided a burrow can be excavated.
Nature of soil and climatic extremes seem to be primary correlates with depth of nest. Water is obtained metabolically from food and from moisture in food. Uses desert flats, or slopes, with sparse to moderate canopy coverages and sandy to gravelly substrates. Territory size less than home range. D. merriami may breed several times a year, although once is the norm.