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

Teton County, Montana; Toole County, Montana; and Treasure County, Montana.  The Teton County Seat is Choteau, Montana; the Toole County Seat is Shelby, Montana; and the Treasure County Seat is Hysham, Montana.