13 cm (5") Common. Western North America. Mountains, open woodlands, coastal areas, suburbs.
Told from similar Tree Swallow by white rump patches that extend upward from the sides to nearly meet at the base of the tail. Also more extensive white on face; the white from the cheek extends upward partially encircling the eye.
Song: rapid twitters "chit-chit-chit-chit wheet, wheet".