Western swordfern occurs along the Pacific Coast from southeastern Alaska south to Baja, California [81,100,126,183], with disjunct populations in northeastern Washington, northern Idaho, northwestern Montana, northeastern Oregon [130,189], and the west Kootenays in British Columbia [74]. Western swordfern is most abundant and widespread in coastal areas from central Vancouver Island and the adjacent mainland southward [170], throughout the western Coast and Cascade ranges [81,100], and into northwestern California [98]. Its latitudinal distribution is described as low-subarctic, high-temperate [183]. Western swordfern occurs in the following states and provinces as of 2014: United States: AK, CA, ID, MT, OR, PA, SD, WA Canada: BC [214], YT [158]