The following maps were made available by Dr. Dan Steck of the Minnesota Radon Project

Map of average radon levels in Minnesota counties
Averages by County
Map of average radon levels in Minnesota by zipcode
Averages by Zipcode
Map of average radon levels in bedrooms of Minnesota homes
Average Bedroom Radon Levels
Map of average outdoor radon levels for the state of Minnesota
Average Outdoor Radon Levels

Attribution : Maps prepared by Dr. Dan Steck, The Minnesota Radon Project .