Ohio magnetic anomaly grid at flight altitude of 1000 feet above ground

Online link ftp://ftpext.usgs.gov/pub/cr/co/denver/musette/pub/GEOPHYSICAL_DATA/non-web_pf_comp/ohio_mag_1000d.gxf
Originators Hildenbrand, Thomas G. and Kucks, Robert P.
Publication U.S. Geological Survey Geophysical Investigations Map 961

States or counties