Forty-eight species and two varieties of the genera Cetraria, Hypogymnia, Parmelia, Parmeliopsis, and Platismatia in the lichen family Parmeliaceae are reported from a 13 400-km2 area in the mountains and foothills of southwestern Alberta. Twelve of these taxa are new to Alberta. The distribution and habitats occupied by each of the taxa are described. Thirty-four (67%) of the taxa are of Circumpolar distribution and 17 (33%) are endemic to North America. The three best represented distribution elements are Circumpolar, Arctic – Boreal Alpine – Montane (13 taxa, 26%); Circumpolar, Boreal Montane (9 taxa, 18%); and American, Cordilleran (12 taxa, 24%). One new combination, Hypogymnia enteromorpha var. inactiva, is proposed.