Eutamias minimus operarius, Howell, Jour. Mamm. 3:183, August 4, 1922.
Type.—Female, adult, skull and skin, No. 129808 (BS); from Gold Hill, 7,400 ft., Boulder County, Colorado; obtained on October 8, 1903, by Vernon Bailey; original No. 8160.
Diagnosis.—Size large; general tone of upper parts dark reddish brown; sides Tawny or Ochraceous-Tawny; baculum large, as in E. m. pallidus.
Description.—Color pattern: Crown Cinnamon-Buff mixed with Pale Smoke Gray; facial stripes Fuscous Black mixed with Sayal Brown; anterior margin of ear and hairs inside posterior part of pinna Cinnamon-Buff; posterior margin of ear and postauricular patch Pale Smoke Gray; dorsal dark stripes black with Ochraceous-Tawny along margins; median dorsal light stripes Pale Smoke Gray with Ochraceous-Tawny along margins; lateral dorsal light stripes white; sides Tawny or Ochraceous-Tawny; rump and thighs Light Grayish Olive; dorsal surface of tail Fuscous Black slightly mixed with Clay Color; ventral surface of tail Sayal Brown or Ochraceous-Tawny with Fuscous Black along margin and Clay Color along outermost edge; antipalmar and antiplantar surfaces of feet Ochraceous-Buff; underparts grayish white, often washed with Buff. Skull and Baculum: Large but of same proportions as in other subspecies of E. minimus.
Comparisons.—For comparisons with E. m. minimus, E. m. pallidus, E. m. confinis, and E. m. silvaticus, see the accounts of those subspecies.
Remarks.—Specimens from the mountains near Savery in Carbon County and from near Medicine Bow Peak in Carbon and Albany counties are clearly referable to this race on the basis of color pattern. However, in the skull and baculum these specimens resemble E. m. minimus.
Specimens from the Laramie Range, 27 mi. N Laramie, show a color pattern which tends toward that of E. m. pallidus.
Specimens examined.—Total number, 118.
Natrona Co.: 2 mi. W and 7 mi. S Casper, 6,370 ft., 2; 10 mi. S Casper, 7,750 ft., 3; 6 mi. S and 2 mi. W Casper, 5,900 ft., 1.
Converse Co.: 21½ mi. S and 24½ mi. W Douglas, 7,600 ft., 10.