Montana air pollution stats

County	First data available	Last data available
Big Horn Co	1997	2006
Broadwater Co	1997	1997
Cascade Co	1997	2007
Fergus Co	1997	2004
Flathead Co	1997	2007
Gallatin Co	1997	2007
Glacier Co	1997	2007
Jefferson Co	1997	2001
Lake Co	1997	2006
Lewis and Clark Co	1997	2007
Lincoln Co	1997	2007
Madison Co	1997	2003
McCone Co	2004	2005
Missoula Co	1997	2007
Musselshell Co	2002	2003
Park Co	1997	1997
Phillips Co	1997	1997
Powell Co	2002	2004
Ravalli Co	1997	2007
Roosevelt Co	1997	2004
Rosebud Co	1997	2006
Sanders Co	1997	2007
Sheridan Co	2002	2004
Silver Bow Co	1997	2007
Stillwater Co	1997	2002
Sweet Grass Co	2001	2006
Yellowstone Co	1997	2007