most of the continental United States, to Central America, down to western Ecuador and northern Venezuela of northern South America. They grow long. In Montana, the milk snake is found in central and southeast portions of the state. Prairie rattlesnake The prairie rattlesnake (Crotalus viridis viridis, Salish: x̣eʔulexʷ) is a venomous pitviper species native to the western United States, southwestern Canada, and northern Mexico. In Montana, this is the only venomous snake in the state but it is common and widespread. Rubber boa The rubber boa (Charina bottae) is a snake in the genus Charina of the family Boidae. Boidae consists of the non-venomous snakes commonly called boas and has 43 species. The genus Charina consists of four species, three of which are found in North America, and one species found in Africa. In Montana, this boa is found in western and southwestern portions of the state. Plains garter snake The plains garter snake (Thamnophis radix) is a species of garter snake native to most of the Central United States stretching as far north as Canada and as far south as Texas. It has a distinctive orange or yellow stripe that goes from its head to tail, the rest of its body is mainly a gray-green color. The snake is commonly found living near water sources such as streams and ponds, but can also be found in urban areas and vacant lots. Common garter snake The valley garter snake (Thamnophis sirtalis fitchi, Salish: sč̓ewíle) is a subspecies of the common garter snake. It is a snake indigenous to North America. Most garter snakes have a pattern of yellow stripes on a brown background and their average length is about . The common garter snake is a diurnal snake. In summer, it is most active in the morning and late afternoon; in cooler seasons or climates, it restricts its activity to the warm afternoons. Terrestrial garter snake The wandering garter snake (Thamnophis elegans vagrans, Salish: sč̓ewíle) is a subspecies of the western terrestrial garter snake, a species of colubrid snake residing only in southwestern Canada, and Western United States. Seven subspecies are currently recognized. Most snakes have a yellow, light orange, or white dorsal stripe, accompanied by two stripes on its side of the same color. Some varieties have red or black spots between the dorsal stripe and the side stripes. This snake often inhabits coniferous forests, and is relatively aquatic.