Warner & Foote, University of Iowa. Libraries. Map Collection. (1886). Geological map of Allamakee County, Iowa. Warner & Foote. http://digital.lib.uiowa.edu:80/cdm/ref/collection/atlases/id/395

Available from: https://geo.btaa.org/catalog/b3e14894-341b-4e7c-bb82-ba4a01797324