The mountain king snake is 100 cm long, with a white snout and nose. The body is mainly red, with white or yellow-white markings, and a black ring on the back.

The King Snake likes to hide under the fallen leaves near the water, under fallen trees. Active during the day, often out in the sun during the cold season. Feeds on small mammals, lizards and other snakes. Mainly distributed from southern Arizona to northern Mexico, inhabiting montane coniferous forests and scrub areas below 2,700 meters above sea level.