This snake often occurs in the vicinity of ponds, sloughs, marshes, lakes, or slow creeks or rivers, generally in prairie and farmland areas but also in the pinyon-juniper zone; it often disperses into adjacent terrestrial habitats, such as vacant lots, residential areas, old dumps, or prairie (Rossman et al. 1996, Hammerson 1999, Ernst and Ernst 2003, Stebbins 2003). Hibernation sites include burrows of rodents or crayfish, crevices, anthills, old wells, spaces under concrete, and other similar sites; some may hibernate underwater.

This species ranges from central United States to south-central Canada. Its range extends from southern Alberta, Montana, eastern Wyoming, eastern Colorado and northeastern New Mexico eastward through southern Manitoba, Minnesota, southern Wisconsin and northern and central Illinois to northwestern Indiana and disjunctly to central Ohio, southward to northern Texas, western Oklahoma, and northern half of Missouri, at elevations of 120 to 2,290 m (400 to 7,500 feet) but usually below 1,830 m (6,000 feet) (Rossman et al. 1996, Hammerson 1999, Ernst and Ernst 2003, Stebbins 2003, Walley et al. 2003).

Many occurrences are in protected areas.