In the south-central part of Boone County is an area that possesses characteristic plants as well as peculiar geological and topographic features. This is located four miles directly south of Boone and extends for about two miles south toward and along the Des Moines River. Its name "The Ledges" is appropriate because of striking sandstone cliffs from ten to over forty feet in height, extending beyond the perpendicular in some cases as much as twelve feet. This ledge rock here comprises an island of younger massive sandstone surrounded unconformably by somewhat older Carboniferous layers, which are of different structure. The conditions peculiar to this restricted locality give the flora a distinctive character.
Proceedings of the Iowa Academy of Science
©1915 Iowa Academy of Science, Inc.
Diehl, William W.
"The Flora of the Ledges Region of Boone County, Iowa,"
Proceedings of the Iowa Academy of Science, 22(1), 77-104.
Available at: https://scholarworks.uni.edu/pias/vol22/iss1/13