With the exception of the tundra extreme north and deep south states of Tennessee, Alabama, Mississippi and Georgia this water foul can be seen in all of North America. Seasonal patterns are like most migrating birds, northern area during summer and nesting, southern areas during winter and the middle during migration.

This merganser is widespread and numerous, especially in areas with fresh water but also occasionally brackish water during winter. These water foul are often seen in large flocks.

Long red bill which is thicker than other mergansers, with a sloping and elongated head. Male is mostly white with a dark greenish head and a dark strip on top back when swimming. Female has chestnut brown head, white throat patch and breast.

In flight, male has a single black bar crossing white on upper wing, female has white speculum crossed by the black bar.