The Sinaloa Martin is a large but poorly known swallow. The male is glossy steel-blue with a white belly and black streaks on the undertail coverts. In the breeding season, it is found in pine-oak forests and semi-open mountainous regions up to 2000 m in the Sierra Madre Occidental in western Mexico, from northeast Sonora south to Jalisco and Michoacán. Little is known about its breeding, clutch size, incubation, or fledging, but it is seen in small groups on its breeding grounds from March through August, and it nests in cavities, probably in trees. Its wintering range is unknown, but most likely inland in South America.