Guanella Pass, in Colorado, is a high, broad ridge that connects the Mt. Evans massif with the Continental Divide. This windswept ridge, 11,669 feet above sea level, is covered by alpine tundra and willow thickets; access is provided by the Guanella Pass Road which connects I-70, at Georgetown, with U.S. 285, at Grant, Colorado. While the roadway can be traversed by the family car through most of the year, a four-wheel drive vehicle is recommended in winter and the route may be closed after periods of heavy snow.
Birders flock to Guanella Pass to see white-tailed ptarmigan, elusive residents of the alpine tundra, which congregate here during the winter months. Smallest of the North American ptarmigans, this species is solid white in winter, blending with the snowy landscape; only its black eyes, bill and red eye comb contrast with the white plumage. The birds are drawn to Guanella by its plentiful willow thickets which provide shelter and nutrition; willow buds are among the highest calorie plant foods.
Winter visitors are advised to wear layered, wind-proof clothing and to bring snowshoes or cross-country skis. While the ptarmigan are occasionally spotted near the parking lots, some exploration is generally needed to find them and efforts are often futile. Binoculars or spotting scopes are essential; look for small groups in thickets on the lee side of large boulders. By April, the ptarmigan will begin molting to their summer plumage and will disperse to nearby mountain ranges.
