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

Harper County, Oklahoma; Haskell County, Oklahoma; and Hughes County, Oklahoma.  The Harper County Seat is Buffalo, Oklahoma; the Haskell County Seat is Stigler, Oklahoma; and the Hughes County Seat is Holdenville, Oklahoma.