Abstract: The Environmental Protection Agency (EPA) compiles data on emission tonnages of air pollutants for US counties.  US Air Quality Gradebook ("AirGrades") source sheets such as this one for Chaffee County, Colorado, and

Cheyenne County, Colorado, give the percentage contributions from specific air pollution sources.  The Chaffee County Seat is Salida, Colorado, and the Cheyenne County Seat is Cheyenne Wells, Colorado.