In 1955, the Carnegie Museum published “Orchids of Western Pennsylvania” by the senior authors. In 1962, Castanea printed “Additions to the Orchids of Western Pennsylvania,” in which we were concerned mainly with bringing up to date the records of the orchid collections in the Carnegie Museum Herbarium. The present treatment is an attempt to indicate the contemporary state of our understanding of the orchids in our region. “Our region” should be interpreted as western Pennsylvania to the eastern borders of Fulton, Huntingdon, Centre, Clinton, and Potter counties, hereinafter written “Western Pennsylvania.”