_Description._--_Color pattern_: Crown Cinnamon Buff mixed with gray; upper facial stripe Sepia; ocular stripe Chaetura-Drab; submalar stripe Fuscous Black mixed with Sayal Brown; ears black; anterior margin of ear Mars Yellow; posterior margin of ear grayish white; hairs inside posterior part of pinna Dresden Brown; postauricular patch Pale Smoke Gray; median dorsal dark stripe black; lateral dorsal dark stripes black mixed with Sayal Brown; outermost dorsal dark stripes Buckhorn Brown mixed with black or sometimes absent; median pair of dorsal light stripes grayish mixed with Buckhorn Brown; outer pair of dorsal light stripes creamy white; sides Buckhorn Brown; rump and thighs Pale Smoke Gray mixed with Saccardo's Umber; dorsal surface of tail black mixed with Buckhorn Brown; ventral surface of tail Sayal Brown, with Fuscous Black around margin and white or Light Buff around outermost edge; antipalmar and antiplantar surfaces of feet Warm Buff; underparts creamy white with dark underfur. _Skull_: Large; zygomata strong and arched; braincase well inflated. _Baculum_: Broad at base; shaft tapers sharply to tip. _Comparisons._--From _E. u. montanus_, the subspecies from the Medicine Bow Range of south-central Wyoming, _E. u. fremonti_ differs in: Over-all tone of upper parts darker; underside of tail darker; feet darker; sides darker. For comparisons with _E. u. umbrinus_ see the account of that subspecies. _Remarks._--This subspecies normally occurs in the forest as do the other subspecies of _E. umbrinus_ in Wyoming. A single specimen taken at 12 mi. N and 3 mi. W Shoshoni, Fremont County, is the exception which probably indicates that _E. umbrinus_ does occur outside of its normal habitat and that gene-flow exists between the subspecies of this species. _Specimens examined._--Total number, 53. _Yellowstone Park_: Unspecified, 2. _Park Co._: Beartooth Lake, 1 (BS); 16-1/4 mi. N and 17 mi. W Cody, 5,625 ft., 2. _Teton Co._: 1 mi. E and 1/4 mi. N Togwotee Pass, 9,800 ft., 2; Amphitheater Lake, Teton Park, 1 (MM); Flat Creek, 4 (MM); head of Cache Creek, 4 (MM); Jackson, Upper Arizona Creek, 2 (MM); Flat Creek-Granite Creek divide, 6 (MM); Flat Creek Pass, 1 (MM); Flat Creek-Gravel Creek divide, 2 (MM). _Lincoln Co._: La Barge Creek, near source, 9,000 ft., 1 (BS). _Fremont Co._: Togwotee Pass, 12 (FC); 12 mi. N and 3 mi. W Shoshoni, 4,650 ft, 1; Mosquito Park R.S., 9,500 ft., 17-1/2 mi. W and 2-1/2 mi. N Lander, 1; 17 mi. S and 6-1/2 mi. W Lander, 8,450 ft., 3. _Sublette Co._: 31 mi. N Pinedale, 8,025 ft., 1; W side Barbara Lake, 10,300 ft., 8 mi. S and 3 mi. W Fremont Peak, 4; 19 mi. W and 2 mi. S Big Piney, 7,700 ft., 5.