White-tailed Ptarmigan (Lugopus leucurus). Photo taken near Grizzly Meadow, Emigrant Wilderness Area, CA, July 1994.

This species is not native to the Sierra range, but was introduced in the 70's as described in the habitat study in the link below. "Seventy-two adult White-tailed Ptarmigan from Colorado were released in the central Sierra Nevada at Eagle Peak and Twin Lakes, Mono County, during 1971-1972 in upper montane-subalpine forest below 3,000 m elevation."

HABITAT USE AND POPULATION CHARACTERISTICS OF
THE WHITE-TAILED PTARMIGAN IN THE
SIERRA NEVADA, CALIFORNIA