2 77
1
1
4
9
3
1117
78
50
18 47
535217 57
56 62
13
67
67
19
6
5
25
6244
21
5754
7
64
55 70
69
63
27
27
72
20 40
40
1
4526
71
65
28
2239
6668
8
73
73
74
63
29
6 38
25
3736
35
23
32
75
30
34
76
49
46
48
5051
23
24
79
33
31
1015 41
58
42
43
5983
58
60
42
17
82
58
84
65
66
61
16
81
12
14
80
Map Source: USEPA, 2003
1 Coast Range 2 Puget Lowland 3 Willamette Valley 4 Cascades 5 Sierra Nevada 6 Southern and Central California Chaparral and Oak Woodlands 7 Central California Valley 8 Southern California Mountains 9 Eastern Cascades Slopes and Foothills10 Columbia Plateau11 Blue Mountains12 Snake River Plain13 Central Basin and Range14 Mojave Basin and Range15 Northern Rockies16 Idaho Batholith17 Middle Rockies18 Wyoming Basin19 Wasatch and Uinta Mountains20 Colorado Plateaus21 Southern Rockies22 Arizona/New Mexico Plateau23 Arizona/New Mexico Mountains24 Chihuahuan Deserts25 Western High Plains26 Southwestern Tablelands27 Central Great Plains28 Flint Hills
29 Central Oklahoma/Texas Plains30 Edwards Plateau31 Southern Texas Plains32 Texas Blackland Prairies33 East Central Texas Plains34 Western Gulf Coastal Plain35 South Central Plains36 Ouachita Mountains37 Arkansas Valley38 Boston Mountains39 Ozark Highlands40 Central Irregular Plains41 Canadian Rockies42 Northwestern Glaciated Plains43 Northwestern Great Plains44 Nebraska Sand Hills45 Piedmont46 Northern Glaciated Plains47 Western Corn Belt Plains48 Lake Agassiz Plain49 Northern Minnesota Wetlands50 Northern Lakes and Forests51 North Central Hardwood Forests52 Driftless Area53 Southeastern Wisconsin Till Plains54 Central Corn Belt Plains55 Eastern Corn Belt Plains56 Southern Michigan/Northern Indiana Drift Plains
57 Huron/Erie Lake Plains58 Northeastern Highlands59 Northeastern Coastal Zone60 Northern Appalachian Plateau and Uplands61 Erie Drift Plain62 North Central Appalachians63 Middle Atlantic Coastal Plain64 Northern Piedmont65 Southeastern Plains66 Blue Ridge67 Ridge and Valley68 Southwestern Appalachians69 Central Appalachians70 Western Allegheny Plateau71 Interior Plateau72 Interior River Valleys and Hills73 Mississippi Alluvial Plain74 Mississippi Valley Loess Plains75 Southern Coastal Plain76 Southern Florida Coastal Plain77 North Cascades78 Klamath Mountains79 Madrean Archipelago80 Northern Basin and Range81 Sonoran Basin and Range82 Laurentian Plains and Hills83 Eastern Great Lakes and Hudson Lowlands84 Atlantic Coastal Pine Barrens
Level III Ecoregions of the Conterminous United States
Atlant ic
Ocean
ChesapeakeBay
James River
York River
Potom
ac Riv er
Delaware River
Lake Erie
BluestoneLake
Allegheny Reservior
Alle
g heny
Riv
er
RaystownLake
Delawa re R
ive r
James River
Lake Anna
Smith Mountain Lake
Leesville Lake
Gre
enbr
ier R
iver
Roanoke River
New River
New River
Ohio
River
Ohi
o R
iver
Ohio River
Schuykill River
Susquehanna River
Susquehanna River
Conemaugh River
PymatuningLake
John H Kerr Reservoir
LakeGaston
Rappahannock River
66
45
63
63
84
64
58
67
62
5860
6261
83
57
5556
56
69
70
71
61c
61b
61c
57a
57b
57d
55a
61c
61d
70c
70e
61c
70b55b
70a
55c
55e
70f
70d
71d
83a
61d
61c
61e
57a
55b
55d
66e
66f67g
67i
66f67i
66d
67i
67h66f
67h
67h
67i67h
67g67f
66e
66e67f
67f
62e60b
60a
62b67c
62c
60a
67e
83a 60a
61c
62d
62c
62a
61b
67b
62d62d
67d
67c
67a
67c
67e
67b67b
67c
67a
67a
67a
70c
69b
67a
67e
67a
67a
67c
67b
69a
58h
64b
64a
67c
64b64a
67a67c
67c67a
67a
67d64d
67b
64c
63a
67a
67b67b
67d
58h
64b
67a67d
67b
64d
64a
67b
64b
64c
69a
64a64b69a
67a
67b 64a
64c64a
66a
70b
66b
70b
63a
70b
67a
65n
69b
64a
67a
67d
67a
64d
67b
67c
67c
67b
63f
67b
70a
67d
67c
63b
67d
67a
66b69b
67c
64d
63b
67c
67c
64c
66b
67b
67d
67c67b
67b
67b
67d
69b
67c
63d
67a
63b
64b
67c
67c
67c
63b
45e
64b
63b
64a
67c
67a
67b
67b 67d
65m
66b
63b
45f
66b
63b
67a
69c
67b
67b
69d
67c69a
67a
66a
63b
67c
67c
67c
45g
67h
67g
45g
66a
63b
67f
63e
67f
67f
63e
67g
67g
63b63d
67f
67i
45g
67h
45c
63c
67f
66e66e
66d
66c
67f
67g
66e
67g
67f67h
67g
67i
67i66e
67i 67i
67f
67g
67h
66d67f 67i
67g
66f67f
67i
69e
69e
67h
66d
CANADA
UNITED STATES
OHIO
MICHIGAN
NORTH CAROLINA
VIRGINIA
TENNESSEE
VIRGINIA
VIRGINIAKENTUCKY
MARYLAND
VIRGINIA
MA
RY
LA
ND
DE
LA
WA
RE
NEW JERSEY
PENNSYLVANIA
PENNSYLVANIANEW YORK
PEN
NSY
LVA
NIA
OH
IO
PENNSYLVANIA
MARYLANDWE
ST V
IRG
INIA
PEN
NSY
LVA
NIA
WEST V
IRGIN
IA
MARYLAND
KENTUC
KY
OHIO
WEST V
IRGIN
IA
OHIO
VIRGINIA
WEST VIRGINIA
NEW
JERSEY
DELAW
AR
EWashington D.C.
TrentonHarrisburg
Dover
Columbus
Annapolis
Charleston
Richmond
BinghamtonElmira
Monticello
Erie
Scranton
Warren
Wilkes-Barre
Stroudsburg
Williamsport
Meadville
Franklin
Easton
Cleveland
Toledo
Allentown
Sandusky
Youngstown
New Castle
Lewistown
Reading
Akron
Butler
Norristown
Huntingdon
Indiana
Philadelphia
Beaver
Canton
Carlisle
Lancaster
Pittsburgh
York
New Cumberland
Wilmington
Steubenville
Chambersburg
Marion
Gettysburg
Elkton
Washington
Somerset
Westminster
Wheeling
Hagerstown
Uniontown
Towson
Cambridge
Moundsville
Cumberland
Chestertown
Frederick
Baltimore
Newark
Martinsburg
Morgantown
CharlesTown
Keyser
Gaithersburg
New Martinsville
Kingwood
Romney
Denton
Springfield
Rockville
Fairmont
Winchester
Georgetown
Easton
Grafton
Arlington
Clarksburg
Marietta
Fairfax
FrontRoyal
Philippi
Cambridge
Manassas
Athens
Parkersburg
Salisbury
Chillicothe
Weston
Buckhannon
Elkins
Culpeper
Ripley
Harrisonburg
PointPleasant
Portsmouth
Staunton
Maysville
Summersville
Huntington
Lexington
Madison
Covington
Morehead
Williamsburg
LewisburgBeckley
Hinton
Fincastle
New Castle
Virginia BeachNorfolk
Bedford
Williamson
Princeton
Welch
Pikeville
Christiansburg
Emporia
Pulaski
Hazard
Wytheville
Martinsville
Marion
AbingdonJonesville
Johnstown
Altoona
Lock Haven
StateCollege
Jamestown
Vineland
Lebanon
Aberdeen
St. Charles
Kingsport
Bristol
Mount AiryEdan
Danville
Roanoke Rapids
Roanoke
Petersburg
Charlottesville
Lynchburg
Farmville
Fredericksburg
Tappahannock
Louisa
Buckingham
Sussex
Dinwiddie
Lunenburg
Bowling Green
Smethport
Emporium
Ridgway
Tionesta
Harrisville
Montrose
Laporte
Sunbury
Marlinton
Franklin
Warrenton
Warm Springs
83° 82° 81° 80° 79° 78° 77° 76° 75°
83° 82° 81° 80° 79° 78° 77° 76° 75°
37°
38°
39°
40°
41°
42°
37°
38°
39°
40°
41°
42°
30 60 mi0
60 120 km01530
10 5
SCALE 1:1 000 000
Albers Equal Area Projection
67 Ridge and Valley67a Northern Limestone/Dolomite Valleys 67b Northern Shale Valleys 67c Northern Sandstone Ridges 67d Northern Dissected Ridges67e Anthracite Subregion67f Southern Limestone/Dolomite Valleys and
Low Rolling Hills67g Southern Shale Valleys 67h Southern Sandstone Ridges67i Southern Dissected Ridges and Knobs
69 Central Appalachians69a Forested Hills and Mountains 69b Uplands and Valleys of Mixed Land Use 69c Greenbriar Karst69d Dissected Appalachian Plateau69e Cumberland Mountain Thrust Block
70 Western Allegheny Plateau70a Permian Hills 70b Monongahela Transition Zone 70c Pittsburgh Low Plateau
83 Eastern Great Lakes and Hudson Lowlands83a Erie Lake Plain
Level III BoundaryLevel IV Boundary State BoundaryCounty Boundary
45 Piedmont45c Carolina Slate Belt45e Northern Inner Piedmont45f Northern Outer Piedmont45g Triassic Basins
58 Northeastern Highlands58h Reading Prong
60 Northern Appalachian Plateau60a Glaciated Low Plateau60b Northeastern Uplands
61 Erie/Ontario Drift And Lake Plains 61b Mosquito Creek/Pymatuning Lowlands 61c Low Lime Drift Plain
62 North Central Appalachians62a Pocono High Plateau62b Low Poconos 62c Glaciated Allegheny High Plateau 62d Unglaciated Allegheny High Plateau62e Low Catskills
63 Middle Atlantic Coastal Plain63a Delaware River Terraces and Uplands63b Chesapeake-Pamlico Lowlands and Tidal
Marshes63c Swamps and Peatlands63d Virginian Barrier Islands and Coastal
Marshes63e Mid-Atlantic Flatwoods 63f Delmarva Uplands
64 Northern Piedmont 64a Triassic Lowlands64b Diabase and Conglomerate Uplands64c Piedmont Uplands64d Piedmont Limestone/Dolomite Lowlands
65 Southeastern Plains65m Rolling Coastal Plain65n Chesapeake Rolling Coastal Plain
66 Blue Ridge66a Northern Igneous Ridges 66b Northern Sedimentary and
Metasedimentary Ridges 66c New River Plateau66d Southern Crystalline Ridges and Mountains66e Southern Sedimentary Ridges66f Limestone Valleys and Coves
Ecoregions denote areas of general similarity in ecosystems and in the type, quality, and quantity of environmental resources; they are designed to serve as a spatial framework for the research, assessment, management, and monitoring of ecosystems and ecosystem components. Ecoregions are directly applicable to the immediate needs of state agencies, including the development of biological criteria and water quality standards and the establishment of management goals for nonpoint-source pollution. They are also relevant to integrated ecosystem management, an ultimate goal of most federal and state resource management agencies.
The approach used to compile this map is based on the premise that ecological regions can be identified through the analysis of the spatial patterns and the composition of biotic and abiotic phenomena that affect or reflect differences in ecosystem quality and integrity (Wiken 1986; Omernik 1987, 1995). These phenomena include geology, physiography, vegetation, climate, soils, land use, wildlife, and hydrology. The relative importance of each characteristic varies from one ecological region to another regardless of the hierarchical level. A Roman numeral hierarchical scheme has been adopted for different levels of ecological regions. Level I is the coarsest level, dividing North America into 15 ecological regions. Level II divides the continent into 52 regions (Commission for Environmental Cooperation Working Group 1997). At level III, the continental United States contains 104 regions (United States Environmental Protection Agency [USEPA],1998). Level IV is a further subdivision of level III ecoregions. Explanations of the methods used to define the USEPA’s ecoregions are given in Omernik (1995), Griffith and others (1994), and Gallant and others (1989).
The level III and IV ecoregion map on this map was compiled at a scale of 1:250,000 and depicts revisions. It revises and subdivides earlier level III ecoregions that were compiled at a smaller scale (USEPA 1998; Omernik 1987). It includes previously published level IV ecoregions (Woods and Omernik, 1996; Woods and others, 1996). It expands level IV coverage to include, for the first time, western West Virginia and the Coastal Plain and Piedmont of Delaware, Maryland, and Virginia. Compilation of this map was part of a collaborative project with the United States Environmental Protection Agency (EPA) Region III Environmental Services Division, the EPA National Health and Environmental Effects Research Laboratory (NHEERL), and state environmental resource management agencies from Pennsylvania, Virginia, Maryland, and West Virginia.
For additional information, contact James M. Omernik, U.S. EPA National Health and Environmental Effects Laboratory (NHEERL), 200 SW 35th Street, Corvallis, OR 97333 (phone: 541-754-4458).
PRINCIPAL AUTHORS: Alan J. Woods (Dynamac Corp.), James M. Omernik (USEPA), and Douglas D. Brown (US Forest Service). Map preparation and development of digital files were provided by Jeffrey A. Comstock, Sandra H. Azevedo, M. Frances Faure, and Suzanne M. Pierson (OAO Corp.).
Literature Cited:
Bailey, R.G., Avers, P.E., King, T., and McNab, W.H., eds., 1994, Ecoregions and subregions of the United States (map) (supplementary table of map unit descriptions compiled and edited by McNab, W.H. and Bailey, R.G.): Washington, D.C., U.S. Department of Agriculture-Forest Service, scale 1:7,500,000.
Commission for Environmental Cooperation Working Group, 1997, Ecological regions of North America - toward a common perspective: Montreal, Quebec, Commission for Environmental Cooperation, 71 p.
Gallant, A.L., Whittier, T.R., Larsen, D.P., Omernik, J.M., and Hughes, R.M., 1989, Regionalization as a tool for managing environmental resources: Corvallis, Oregon, U.S. Environmental Protection Agency EPA/600/3-89/060, 152 p.
Griffith, G.E., J.M. Omernik, and S.H. Azevedo. 1998. Ecoregions of Tennessee. (Map poster). U.S. Geological Survey, Reston, VA.
Griffith, G.E., Omernik, J.M., Wilton, T.F., and Pierson, S.M., 1994, Ecoregions and subregions of Iowa - a framework for water quality assessment and management: The Journal of the Iowa Academy of Science, v. 101, no. 1, p. 5-13.
Omernik, J.M., 1987, Ecoregions of the conterminous United States (map supplement): Annals of the Association of American Geographers, v. 77, no. 1, p. 118-125, scale 1:7,500,000.
Omernik, J.M., 1995, Ecoregions-a framework for environmental management, in Davis, W.S. and Simon, T.P., eds., Biological assessment and criteria-tools for water resource planning and decision making: Boca Raton, Florida, Lewis Publishers, p. 49-62.
U.S. Department of Agriculture-Soil Conservation Service, 1981, Land resource regions and major land resource areas of the United States: Agriculture Handbook 296, 156 p.
U.S. Environmental Protection Agency, 1998, Level III ecoregions of the continental United States (revision of Omernik, 1987): Corvallis, Oregon, U.S. Environmental Protection Agency-National Health and Environmental Effects Research Laboratory Map M-1, various scales.
Wiken, E., 1986, Terrestrial ecozones of Canada: Ottawa, Environment Canada, Ecological Land Classification Series no. 19, 26 p. Woods, A.J., and Omernik, J.M., 1996, Ecoregions of Pennsylvania; Pennsylvania Geographer, v. XXXIV, no. 2, p. 3-37.
Woods, A.J., Omernik, J.M., Brown, D.D., and Kiilsgaard, C.W., 1996, Level III and IV Ecoregions of Pennsylvania and the Blue Ridge Mountains, the Ridge and Valley, and the Central Appalachians of Virginia, West Virginia, and Maryland: Corvallis, Oregon, U.S. Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, EPA/600R-96/077, 50 p.
Woods, A.J., J.M. Omernik, C.S. Brockman, T.D. Gerber, W.D. Hosteter, and S.H. Azevedo. 1998. Ecoregions of Indiana and Ohio. (Map poster). U.S.
Geological Survey, Reston, VA.
Level I I I and IV Ecoregions of EPA Region 3
jc/aw //uber2//jobs/j420.alan.reg3//reg3.aml //Cisco/ecoregions_final/EPA Reg3/reg3_eco5_03.ai May 28, 2003
