"Lagopus leucurus. White-tailed Ptarmigan. Rocky Mountain Snow Grouse. Male and Female in winter: Entirely snow-white; bill black, rather slender, and general size and proportions nearly as in L. rupestris. Male and female, in summer: Tail, most of the wing, and lower parts from the breast, remaining white; rest of the plumage minutely marked with black, white, and tawny or grayish-brown, varying in precise character almost with every specimen; but there is no difficulty in recognizing this whit-tailed species, of alpine distribution in Western N. A. from the Arctic regions to New Mexico (lat. 37 degrees)." Elliot Coues, 1884

White-tailed Ptarmigan

"Lagopus leucurus. White-tailed Ptarmigan. Rocky Mountain Snow Grouse. Male and Female in winter: Entirely…