Abstract: The Environmental Protection Agency (EPA) compiles data on emission tonnages of air pollutants for US counties.  US Air Quality Gradebook ("AirGrades") source sheets give the percentage contributions from specific air pollution sources.  This source sheet is for

Liberty County, Montana; Lincoln County, Montana; and Madison County, Montana.  The Liberty County Seat is Chester, Montana; the Lincoln County Seat is Libby, Montana; and the Madison County Seat is Virginia City, Montana.