(Minnesota)
Hill-Annex Mine State Park is a former state park of Minnesota, United States, interpreting the open-pit mining heritage of the Mesabi Range. The park was located north of the city of Calumet, in Itasca County, Minnesota. The park provided access to fossil material exposed by mining from the Cretaceous era Coleraine Formation. (Ref: https://en.wikipedia.org/wiki/Hill-Annex_Mine_State_Park)