We studied epiphytic macrolichen communities and occurrences of rare species along the transition from upland to riparian forests on a range of stream sizes (intermittent, non-fish-bearing perennial, fish-bearing but less than 5^th order, and streams larger than 5^th order), based on 92, 0.38 ha plots in the McKenzie River watershed of the central Cascades of Oregon. The transition from uplands higher in the watershed to riparian areas along large streams is expressed in decreasing elevation and increasing representation of hardwoods. Upland stands were almost 100% conifers, averaging 49 m²/ha in stand basal area, decreasing to 48% conifers along fish-bearing streams of fourth order and below, and finally to 30% along large streams. Stand basal areas of hardwoods averaged near zero in uplands, increasing to an average of 11 m²/ha along large streams. One NMS ordination axis described this gradient in macrolichen communities, expressing 72% of the variation in community composition. Epiphytic lichens along large streams differed from fish-bearing streams smaller than fifth order; both of these stream classes also differed strongly from each of the other stream classes. Epiphytic lichens in uplands, along intermittent streams, and non-fish-bearing streams overlapped broadly in species composition. Macrolichen species richness was highest along large streams, averaging 38 species per plot, versus about 28 species per plot for uplands and non-fish-bearing streams. This difference is attributable to more species of cyanolichens, matrix lichens, and nitrophilous lichens along the large streams. About half of the individual species differed in abundance among stream classes, based on Indicator Species Analysis. Listed species (considered at risk by a government agency) were 57% more frequent in riparian areas along large streams than in uplands or along small streams. Protecting riparian zones from logging and urbanization and other forms of habitat destruction will, therefore, protect many rare species. Uplands and small streams, however, supported distinctive macrolichen communities, including rare species that were infrequent or absent from the riparian zones of large streams.