The mountain bluebird, also called the Arctic bluebird and Rocky Mountain bluebird, has an average length of 6.5 to 7.75 inches (16.5 - 20 cm). Males sing a clear short warble, higher pitched than that of the eastern bluebird. Males are all turquoise blue with a paler blue and white belly below. The female's coloring is a dull brown to gray with blue on the rump, wing tips, and tail.