From Dipodomys ordii cupidineus, longipes, nexilis, uintensis and sanrafaeli, D. o. fremonti can readily be distinguished by its smaller size and generally darker color.
Remarks.—This subspecies of Dipodomys ordii inhabits the upper reaches of the Fremont River in west-central Wayne County, Utah. D. o. fremonti appears to be isolated and is known only from the type locality. D. o. fremonti is so remarkably different from any other subspecies of Dipodomys ordii that a long period of isolation from the ancestral stock (which probably gave rise also to Dipodomys ordii utahensis and Dipodomys ordii panguitchensis) is indicated. Although intergradation is not known to occur with other kinds, differentiation has not progressed far enough for these animals to be recognized as a distinct species.
The subspecies closest, geographically, to D. o. fremonti is D. o. cupidineus from which D. o. fremonti differs more than from any of the other named forms.
Specimens examined.—Total, 9, from Utah, as follows: Wayne County: Torrey, 7000 ft., 9 (CM).
Dipodomys ordii uintensis [Durrant and Setzer]
Dipodomys ordii uintensis [Durrant and Setzer], Bull. Univ. Utah, 35 (no. 26):27, June 30, 1945.
Perodipus longipes, Allen, Bull. Amer. Mus. Nat. Hist., 8:246, November 1896 (part—the part from Uncompahgre Indian Reservation, Utah).
Dipodomys ordii luteolus, Moore, Journ. Mamm., 11:88, February, 1930 (part—the part from Vernal, Utah).
Type.—Male, adult, no. 11634, Carnegie Museum, Pittsburgh, Pennsylvania; Red Creek, 6,700 ft., 2 mi. N Fruitland, Duchesne County, Utah; obtained on August 15, 1936, by J. K. and M. T. Doutt, original no. 3433.
Range.—Uinta basin of the White, Green and Duchesne river drainage in northeastern Utah; marginal occurrences are: 2 mi. N Fruitland, 10 mi. S Ouray, Vernal.