This report describes data collected from an aeromagnetic survey flown over an area of central Colorado that includes parts of Chaffee, Eagle, Lake, Park, and Summit Counties, including the towns of Leadville and Buena Vista and parts of the Mosquito Range, Gore Range, and Sawatch Mtns. These data werecollected by Goldak Airborne Surveys on contract to the U.S. Geological Survey (USGS).