This publication provides digital flight line data for a high-resolution magnetic survey over an area of the central Upper Peninsula of Michigan. The survey area lies approximately between the towns of Iron Mountain and Chatham. Data for this survey were collected by EON Geosciences under contract with the USGS using a fixed wing aircraft with a magnetometer mounted in the tail stinger. The survey operated out of the Sawyer International Airport near Marquette, Michigan, from June of 2018 to September of 2018. A total of 38,474 line km of data were collected. Data were collected along north-south flight lines spaced 150 meters apart with east-west tie lines flown every 1,500 meters. The nominal terrain clearance was 80 meters, although greater terrain clearances were required in several areas due to safety concerns. Files that are available in this publication include flight line data for the magnetic survey and a report describing the survey parameters, field operations, quality control and data reduction procedures. A zip file is provided that contains the contractor's deliverable products that includes Geosoft databases and grids for the magnetic survey and the report describing the survey and data reduction. Data have been redacted over two small areas (less than 1 km2 combined) near Sawyer International Airport that include multiple tracts of Native American lands.