PHYS_C	PHYS_D
1	PACIFIC MOUNTAIN DIVISION
1A	COAST RANGES
1B	PUGET-WILLAMETTE LOWLAND
1C	CASCADE KLAMATH-SIERRA NEVADA RANGES
1D	CENTRAL VALLEY OF CALIFORNIA
2	INTERMONTANE DIVISION
2A	COLUMBIA BASIN
2B	HARNEY-OWYHEE BROKEN LANDS
2C	SNAKE RIVER LOWLAND
2D	BASIN AND RANGE AREA
2E	COLORADO RIVER PLATEAUS
2F	UPPER GILA MOUNTAINS
3	ROCKY MOUNTAIN DIVISION
3A	NORTHERN ROCKY MOUNTAINS
3B	BLUE MOUNTAINS
3C	MIDDLE ROCKY MOUNTAINS
3D	SOUTHERN ROCKY MOUNTAINS
4	INTERIOR DIVISION
4A	NORTH-CENTRAL LAKE-SWAMP-MORAINE PLAINS
4B	UPPER MISSOURI BASIN BROKEN LANDS
4C	WYOMING-BIG HORN BASINS
4D	NEBRASKA SAND HILLS
4E	HIGH PLAINS
4F	ROCKY MOUNTAIN PIEDMONT
4G	MID-CONTINENT PLAINS AND ESCARPMENTS
4H	STOCKTON-BALCONES ESCARPMENT
4I	WEST-CENTRAL ROLLING HILLS
4J	MIDDLE WESTERN UPLAND PLAIN
4K	DAKOTA-MINNESOTA DRIFT & LAKE-BED FLATS
4L	SOUTHWEST WISCONSIN HILLS
4M	EAST-CENTRAL DRIFT AND LAKE-BED FLATS
5	EASTERN HIGHLAND DIVISION
5A	OZARK-OUACHITA HIGHLANDS
5B	EASTERN INTERIOR UPLANDS AND BASINS
5C	APPALACHIAN HIGHLANDS
5D	ADIRONDACK-NEW ENGLAND HIGHLANDS
6	GULF-ATLANTIC DIVISION
6A	GULF-ATLANTIC ROLLING PLAIN
6B	GULF-ATLANTIC COASTAL FLATS
6C	LOWER MISSISSIPPI ALLUVIAL PLAIN
6D	LOWER NEW ENGLAND