_Description._--_Color pattern_: Crown Pale Smoke Gray; facial stripes Fuscous Black or Snuff-Brown; ears Fuscous Black; posterior margin of ear and postauricular patch grayish white; median dorsal dark stripe black with Sayal Brown along margins; lateral pair of dorsal dark stripes Fuscous Black mixed with Sayal Brown, or entirely Sayal Brown; outermost pair of dorsal dark stripes Sayal Brown mixed with Fuscous Black or lacking; sides Sayal Brown mixed with Cinnamon; rump and thighs Sayal Brown mixed with Smoke Gray; antipalmar and antiplantar surfaces of feet Cinnamon Buff; underside of tail Ochraceous Tawny or Sayal Brown, with Fuscous Black around margin and Pinkish Buff around outermost edge; underparts creamy white with dark gray underfur. _Skull_: Smooth and rounded; braincase inflated; zygomata strong. _Baculum_: Broadened at base; shaft tapers rapidly to tip. _Comparisons._--From _E. u. fremonti_, the subspecies from the north in the mountains of northwestern Wyoming, _E. u. umbrinus_ differs in: Over-all tone of upper parts darker; sides lighter; skull smaller. From _E. u. montanus_, the subspecies from the Medicine Bow Range of south-central Wyoming, _E. u. umbrinus_ differs in: Over-all tone of upper parts darker; sides darker; skull smaller. _Remarks._--This subspecies occurs only in the foothills of the Uinta Mountains in the southern part of Uinta County. These "foothills" are well-timbered and at an altitude of 7,000 feet and higher. _Specimens examined._--Total number, 23. _Uinta Co._: 9 mi. S Robertson, 8,000 ft, 15; 10 mi. S and 1 mi. W Robertson, 8,700 ft., 5; 11-1/2 mi. S and 2 mi. E Robertson, 9,200 ft., 1; 2 mi. E and 12 mi. S Robertson, Ashley Nat. Forest, 1; 13 mi. S and 2 mi. E Robertson, 9,200 ft., 1. _Additional records_ (Howell 1929:95): _Uinta Co._: Henry Fork, 5 mi. W Lone Tree; Lone Tree. Eutamias umbrinus fremonti White _Eutamias umbrinus fremonti_ White, Univ. Kansas Publ., Mus. Nat. Hist. 5:575, December 1, 1953. _Type._--Male, adult, skull, skin, and baculum, No. 41790 (KU); from 31 mi. N Pinedale, 8,025 ft., Sublette County, Wyoming; obtained on July 8, 1951, by Rollin H. Baker; original No. 1596. _Diagnosis._--Size large; over-all tone of upper parts dark; lower tooth-row longest of this species in Wyoming.