Penrose, Laurie. A guide to 199 Michigan waterfalls / [electronic resource] / text, Laurie Penrose ; maps, Bill T. Penrose ; black and white photos, Ruth Penrose ; field coordinator, Bill J. Penrose.. — Davison, Mich. : : Friede Publications,, c1988.. — xiii, 184 p. : : ill., maps ; 23 cm.