U.S. Fish and Wildlife Service

Data Element:  ECOSYSTEM UNIT NUMBER

Description: One_ and two_digit numbers that represent the ecosystem unit boundaries of the United States, which are drawn primarily along watershed boundaries.

Revision Date:  April 4, 2003

ECOSYSTEM	ECONUM	LEAD
REGION	
NOT APPLICABLE	00	0	
NORTH PACIFIC COAST	01	1	
KLAMATH/CENTRAL PACIFIC COAST	02	1	
CENTRAL VALLEY OF CALIFORNIA/SAN FRANCISCO BAY	03	1	
SOUTHERN CALIFORNIA	04	1	
COLUMBIA BASIN	05	1	
INTERIOR BASIN	06	1	
LOWER COLORADO RIVER	07	2	
GILA/SALT/VERDE RIVER	08	2	
MIDDLE AND UPPER RIO GRANDE	09	2	
LOWER RIO GRANDE	10	2	
PECOS RIVER	11	2	
EDWARDS PLATEAU	12	2	
EAST TEXAS	13	2.	
TEXAS GULF COAST	14	2	
ARKANSAS/RED RIVERS	15	2	
SOUTHERN APPALACHIANS	16	4	
UPPER COLORADO RIVER	17	6	
PLATTE/KANSAS RIVERS	18	6	
UPPER MISSOURI, YELLOWSTONE AND UPPER COLUMBIA RIVER	19	6	
MISSOURI MAIN STEM	20	6	
LOWER MISSOURI RIVER	21	3	
MISSISSIPPI HEADWATERS/TALLGRASS PRAIRIE	22	3	
UPPER MISSISSIPPI RIVER/TALLGRASS PRAIRIE	23	3	
GREAT LAKES	24	3	
OZARK WATERSHEDS	25	3	
OHIO RIVER VALLEY	26	5	
LOWER MISSISSIPPI RIVER	27	4	
TENNESSEE/CUMBERLAND RIVER	28	4	
CENTRAL GULF WATERSHEDS	29	4	
FLORIDA PANHANDLE WATERSHEDS	30	4	
ALTAMAHA WATERSHEDS	31	4	
PENINSULAR FLORIDA	32	4	
SAVANNAH/SANTEE/PEE DEE RIVERS	33	4	
ROANOKE/TAR/NEUSE/CAPE FEAR RIVERS	34	4	
CARRIBEAN	35	4	
DELAWARE RIVER/DELMARVA COASTAL AREA	36	5	
HUDSON RIVER/NEW YORK BIGHT	37	5	
CONNECTICUT RIVER/LONG ISLAND SOUND	38	5	
GULF OF MAINE RIVERS	39	5	
LAKE CHAMPLAIN	40	5	
CHESAPEAKE BAY/SUSQUEHANNA RIVER	41	5	
PACIFIC ISLANDS	42	1	
ARCTIC ALASKA	43	7	
NORTHWEST ALASKA	44	7	
INTERIOR ALASKA	45	7	
SOUTHEAST ALASKA	46	7	
SOUTH CENTRAL ALASKA	47	7	
BRISTOL BAY/KODIAK	48	7	
YUKON-KUSKOKWIM DELTA	49	7	
BERING SEA/ALEUTIAN ISLANDS	50	7	
BEAUFORT/CHUKCHI SEAS	51	7	
NORTH PACIFIC/GULF OF ALASKA	52	7	
SOUTH FLORIDA	53	4