A list oflichen species found in Glacier National Park, Montana, is presented, including notes on relative abundance, substrate, and habitat. Four hundred twenty-five species in 106 genera are reported, including 137 species previously unpublished for Montana. The diversity of Glacier National Park's lichen flora is enhanced by the wide variety of available substrates, an elevational gradient from 970 to 3,190 m, and the Park's position astride the continental divide. The lichen flora of Glacier National Park, located in northwestern Montana, is poorly known. A sys- tematic park-wide field survey has never been con- ducted. Habeck (1963) listed 22 macrolichen spe-