_Range._--Southeastern Washington, eastern Oregon, southwestern Idaho, northwestern, northern and most of northeastern Nevada; marginal occurrences are: in Washington, 2 mi. SW Paterson, 4 mi. E Burbank and Wallula; in Oregon, 7 mi. E Madras, 2 mi. E Prineville and Guano Valley; in California, Eagleville, Red Rock, Observation Peak, 5 mi. E Litchfield, Honey Lake, Vinton; in Nevada, 3-1/2 mi. E Flanigan, 6 mi. S Pahrum Peak, 2-1/2 mi. E and 11 mi. N Gerlach, 2 mi. SW Quinn River Crossing, 1 mi. SE Tuscarora, 5 mi. N Beowawe, 1/2 mi. S Beowawe, 2-1/2 mi. NE Smiths Creek Ranch, Bells Ranch, 5 mi. W Austin, 8 mi. W Eureka, 4 mi. S Shoshone, 5 mi. SE Greens Ranch, and 22 mi. N Deeth; in Idaho, 8 mi. W Rodgerson, 6 mi. SW American Falls, 4 mi. NE American Falls, 5 mi. NW Michaud, Arco, Hammett and Payette; in Oregon, Umatilla. _Diagnosis._--Size medium (see measurements). Color dark, entire dorsal surface (_16''_) between Pinkish Cinnamon and Cinnamon-Buff, purest on sides and flanks with strong admixture of black on upper parts; cheeks white; arietiform markings, pinnae of ears, plantar surfaces of hind feet, dorsal and ventral stripes of tail, blackish. Skull medium in size; rostrum relatively long and narrow; nasals long and expanded distally; interorbital region narrow; lacrimal processes small; braincase but slightly vaulted; auditory bullae relatively greatly inflated; pterygoid fossae circular; zygomatic arches robust. _Comparisons._--From _Dipodomys ordii utahensis_, _D. o. columbianus_ differs as follows: Color lighter, dorsal and ventral stripes of tail brownish as opposed to black; ventral stripe of tail, in most specimens, incomplete to end of pencil as opposed to complete; lacrimal processes smaller; extension of premaxillae dorsad wider; interparietal generally narrower, smaller, quadrangular and truncate anteriorly, as opposed to spatulate and rounded anteriorly; braincase less vaulted; zygomatic arches bowed laterally as opposed to straight; styloid processes larger; cutting edge of upper incisors narrower. From _Dipodomys ordii fetosus_, _D. o. columbianus_ differs in: Hind foot shorter; color generally darker; skull larger; rostrum shorter and wider; nasals somewhat shorter; braincase more vaulted; auditory bullae less inflated; interparietal region wider; ventral border of foramen magnum more rounded (less indented); zygomatic arches straight as opposed to bowed laterally. For comparisons with _Dipodomys ordii inaquosus_, _Dipodomys ordii monoensis_ and _Dipodomys ordii celeripes_ see accounts of those subspecies.