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

Valley County, Montana; Wheatland County, Montana; and Wibaux County, Montana.  The Valley County Seat is Glasgow, Montana; the Wheatland County Seat is Harlowton, Montana; and the Wibaux County Seat is Wibaux, Montana.