A region unified by its physical attributes, especially its latitude, relief and structure, and location. Lane et al. (2004) Australian Geog. Studs 42, 3 argue that the ‘natural’ region is a highly contested concept. Even so, in Canada, federal and provincial park and protected area system plans adopt natural region representation approaches (Lemieux and Scott (2005) Canad. Geog./Géog. canad. 49, 4).