Iŋyaŋ Tiyopa (Stone Door), a natural limestone arch in Frontenac State Park sacred to Dakota and Meskwaki people. Photograph by Wikimedia Commons user McGhiever, October 3, 2012. CC BY-SA 3.0.
Labeled aerial photo showing the boundaries and trails of Frontenac State Park. From page fifteen of “Frontenac State Park Management Plan,” Minnesota Department of Natural Resources, Division of Parks and Recreation, November 2008.