1. Geologic map of the Ontonagon and part of the Wakefield 30ʹ x 60ʹ quadrangles, Michigan, a digital representation of Map I-2499 (1995) [computer file] Yale Public content 2001. 2002-06-01T04:00:00Z. 2023-02-11T04:46:17Z. Geological Survey (U.S.). The Survey ; For sale by USGS Information Services (Open-File Report Sales). English. Public. Michigan, Ontonagon County, and Gogebic County.