The range of this species extends from the Pacific coast to the Atlantic coast of North America (Conant and Collins 1991, Stebbins 2003). The northern limit of the more or less continuous portion of the range reaches Nova Scotia, southern Quebec, southern Ontario in Canada, Minnesota, southeastern South Dakota, eastern Nebraska, southeastern Colorado, and Arizona in the United States. The southern limit extends to San Luis Potosi (Mexico), the Gulf Coast of the United States, and southern Florida. The species also occurs disjunctly in western North America in eastern Washington, eastern Oregon, Idaho, Nevada, Utah, and Arizona, and it ranges from southern Washington through western Oregon and throughout much of California (except the Central Valley and deserts) into northwestern Baja California, including Islas Todos Santos and San Martin along the Pacific Coast (Grismer 2002). This species has been introduced on Grand Cayman Island (probably via ornamental plants from southern Florida), but it is unknown whether or not the species is established there (Schwartz and Henderson 1991).