Hill-Annex Mine State Park, north of Calumet on the Mesabi Range, preserved both Minnesota’s open-pit iron mining heritage and a rare fossil-bearing landscape in the Cretaceous Coleraine Formation until its permanent closure in 2024. Mining began after leases in 1892 and 1900, with extraction starting in 1913, and the mine eventually produced 63 million tons of iron ore, making it Minnesota’s sixth largest producer. Surviving buildings and later museum use reflected its industrial past, while restoration brought back wildlife. Paleontological work since 2014 uncovered many previously undocumented specimens, including a dromaeosaur toe bone in 2015, only the second dinosaur remain identified in Minnesota.