Willow ptarmigan by the fact that it is not generally found above the tree line while the rock ptarmigan prefers more elevated, barren habitat. The summer plumage is browner and in the winter, the male willow ptarmigan lacks the rock ptarmigan's black stripe between the eyes and bill. The white-tailed ptarmigan ("Lagopus leucura") in North America is smaller, has a white tail and finely-barred greyer plumage and lives permanently above the tree line. The distinctive British Isles subspecies "L. l. scoticus" (red grouse) was once considered a separate true British species but is now classified as a sub-species. This moorland bird is
Ptarmigan Pass (Sawatch Range) the Eagle River Valley near Red Cliff. Ptarmigan Pass (Sawatch Range) Ptarmigan Pass (elevation 11,765 ft) is a high mountain pass in the Rocky Mountains of central Colorado in the United States. It is located on the crest of the northern end of the Sawatch Range, along the border of Eagle and Summit counties, south of Vail Pass. The pass is traversed by a jeep trail that is passable by four-wheel drive vehicles and on foot. 2WD vehicles will only make it to the summit from the west; the east side is rocky and boggy at times. The trail connects