Range. - Western United States south of Canada, and chiefly in the Rocky Mountains, and in California ranges, north to Lat. 38°. A handsome species, 6.5 inches in length, with blackish upper parts and sides, and white throat, breast and central line of under parts, flank patches and ends of secondaries; tail feathers not spined or stiffened. These birds are fairly common in some localities within their range, but appear to be found only on high ranges or in their immediate vicinity. They nest in crevices and caves in the face of cliffs, making a nest similar in construc tion to that of the Chimney Swift but of weed stalks instead of twigs, and lined with feathers. They lay four or five dull white eggs, during June or July; size .85 x .50.

White.