DeBolt and McCune (1993, pp.203-204) list 14 species of Umbilicaria from Glacier NP. Two species are "very common" -- hyperborea and krascheninnikovii -- and three are "common" -- deusta, vellea, and virginis, but note that Poelt and Nash split americana from vellea in 1993 after the DeBolt and McCune paper had appeared, so "vellea" in DeBolt and McCune would refer to one or another or both of vellea and americana. In fact, I have photos of americana from Sun Point.