Strata	Primary Unit 	Back-up Unit	Strata	Primary Unit 	Back-up Unit 	
R-1	Helena 	Lolo	R-8	Mississippi	LBL	
R-2	Pike San Isabel	GMUG	R-9	Hiawatha	Huron-Manistee	
R-3	Prescott	Gila	R-10	R-10	Chugach	
R-4	Fishlake	Ashley	Other 	San Dimas	PSW Station	
R-5	Mendocino	Modoc	Other	WO	Missoula T&DC	
R-6	Umpqua	Gifford Pinchot	Other	GSTC	PNW Station	
Environmental Management System Audit Units and Back-ups