One of the Appalachian spleenworts, A. montanum is found in the Appalachian Mountains from Vermont and Massachusetts southwestward to Tennessee, Alabama, and Georgia, and to a lesser extent in the Ohio Valley in Ohio, Indiana, and Kentucky. Arkansas populations were discovered in Garland County and Stone County in 2002 and 2008, respectively. One outlying population in Missouri, collected in 1960, is considered historical; it is represented by one specimen collected near Graham Cave and has never been relocated. The site is thought to have been destroyed by road construction. A collection by Farwell from the Keweenaw Peninsula of Michigan was considered valid by M. L. Fernald, but is of questionable authenticity; the population has never been relocated.