The smooth green snake (Opheodrys vernalis) is a nonvenomous North American colubrid. It is also referred to as the grass snake. It is a slender, "small medium" snake that measures 36–51 cm (14–20 in) as an adult. It gets its common name from its smooth dorsal scales, as opposed to the rough green snake, which has keeled dorsal scales. It is found in marshes, meadows, open woods, and along stream edges and is native to regions of Canada, Maine, Illinois, Virginia, Wyoming, New Mexico and Lowa.