{"type": {"key": "/type/work"}, "title": "Options for National Park Service involvement in the management of historic copper mining resources on Michigan's Keweenaw Peninsula", "subjects": ["History", "Copper mines and mining", "Historic sites"], "subject_places": ["Keweenaw Peninsula (Mich.)", "Michigan", "Keweenaw Peninsula", "Keweenaw National Historical Park (Mich.)"], "authors": [{"type": {"key": "/type/author_role"}, "author": {"key": "/authors/OL4621605A"}}], "key": "/works/OL45480995W", "latest_revision": 1, "revision": 1, "created": {"type": "/type/datetime", "value": "2026-05-18T11:23:35.784338"}, "last_modified": {"type": "/type/datetime", "value": "2026-05-18T11:23:35.784338"}}