Appendix B
Approximate areas and proportionate extent of subregions at the Province and Section level
in the United States (Area is given in square miles rounded to nearest 100, and percentage
to nearest tenth.)
Extent Extent
in in
Province Section Area Province U.S.
\hrule
mi2 % %
124\lf 124A-Coastal Plain\lf 19,100 0.5
125\lf \lf 46,900 1.3
125A-Kotzebue Sound Lowlands\lf 12,100 25.8 0.3
125B-Yukon-Kuskokwim Delta\lf 34,800 74.2 1.0
126\lf 126A-Bristol Bay Lowlands\lf 23,600 0.7
M121\lf \lf 101,600 2.8
M121A-Foothills\lf 47,200 46.5 1.3
M121B-Mountains\lf 54,400 53.5 1.5
M125\lf M125A-Seward Mountains\lf 20,600 0.6
M126\lf M126A-Ahklun Mountains\lf 16,700 0.5
M127\lf \lf 22,200 0.6
M127A-Alaska Peninsula\lf 14,600 65.7 0.4
M127B-Aleutian Islands\lf 4,500 20.3 0.1
M127C-West Kodiak Island\lf 3,100 14.0 0.1
131\lf \lf 56,100 1.6
131A-Upper Kobuk Valley\lf 16,900 30.1 0.5
131B-Yukon-Kuskokwim Bottomlands\lf 39,200 69.9 1.1
135\lf \lf 15,700 0.5
135A-Cook Inlet Lowlands\lf 9,600 61.1 0.3
135B-Copper River Basin\lf 6,100 38.9 0.2
139\lf 139A-Upper Yukon Flats\lf 13,000 0.4
M131\lf \lf 55,000 1.5
M131A-Nulato Hills\lf 19,600 35.6 0.5
M131B-Kuskokwim Mountains\lf 26,200 47.7 0.7
M131C-Nushagak-Lime Hills\lf 9,200 16.7 0.3
M135\lf \lf 61,000 1.7
M135A-Alaska Mountains\lf 48,100 78.9 1.3
M135B-Wrangell Mountains\lf 12,900 21.1 0.4
M139\lf M139A-Upper Yukon Highlands\lf 68,400 1.9
\hrule
Extent Extent
in in
Province Section Area Province U.S.
\hrule
mi2 % %
212\lf \lf 147,300 4.1
212A-Aroostook Hills and Lowlands\lf 3,800 2.6 0.1
212B-Maine and New Brunswick Foothills and
Eastern Lowlands\lf 6,700 4.6 0.2
212C-Fundy Coastal and Interior\lf 2,400 1.6 0.1
212D-Central Maine Coastal and Interior\lf 4,600 3.1 0.1
212E-St. Lawrence and Champlain Valley\lf 4,600 3.1 0.1
212F-Northern Glaciated Allegheny Plateau\lf 21,300 14.5 0.6
212G-Northern Unglaciated Allegheny Plateau\lf 5,900 4.0 0.2
212H-Northern Great Lakes\lf 31,100 21.1 0.9
212J-Southern Superior Uplands\lf 30,300 20.6 0.8
212K-Western Superior\lf 8,200 5.6 0.2
212L-Northern Superior Uplands\lf 7,400 5.0 0.2
212M-Northern Minnesota and Ontario\lf 9,200 6.2 0.3
212N-Northern Minnesota Draft and Lake Plains\lf 11,800 8.0 0.3
M212\lf \lf 43,600 1.2
M212A-White Mountains\lf 17,600 40.4 0.4
M212B-New England Piedmont\lf 6,100 14.0 0.2
M212C-Green, Taconic, Berkshire Mountains\lf 7,100 16.3 0.2
M212D-Adirondack Highlands\lf 10,300 23.6 0.3
M212E-Catskill Mountains\lf 2,500 5.7 0.1
221\lf \lf 104,500 2.9
221A-Lower New England\lf 19,500 18.7 0.5
221B-Hudson Valley\lf 5,800 5.5 0.1
221C-Upper Atlantic Coastal Plain\lf 5,300 5.1 0.1
221D-Northern Appalachian Piedmont\lf 8,000 7.7 0.2
221E-Southern Unglaciated Allegheny Plateau\lf 31,500 30.1 0.9
221F-Western Glaciated Allegheny Plateau\lf 11,800 11.3 0.3
221H-Northern Cumberland Plateau\lf 13,800 13.2 0.4
221I-Southern Cumberland Mountains\lf 3,800 3.6 0.1
221J-Central Ridge and Valley\lf 5,000 4.8 0.1
222\lf \lf 270,000 7.5
222A-Ozark Highlands\lf 45,800 17.0 1.3
222C-Upper Gulf Coastal Plain\lf 10,600 3.9 0.3
222D-Interior Low Plateau, Shawnee Hills\lf 14,100 5.2 0.4
222E-Interior Low Plateau, Highland Rim\lf 29,400 10.9 0.8
222F-Interior Low Plateau, Bluegrass\lf 15,500 5.7 0.4
222G-Central Till Plains, Oak-Hickory\lf 16,000 5.9 0.4
222H-Central Till Plains, Beech-Maple\lf 27,100 10.0 0.8
222I-Erie and Ontario Lake Plain\lf 18,800 7.0 0.5
222J-South Central Great Lakes\lf 25,300 9.4 0.7
222K-Southwestern Great Lakes Morainal\lf 18,000 6.7 0.5
222L-North-Central U.S. Driftless and Escarpment\lf 16,600 6.1 0.5
222M-Minnesota and Northeastern Iowa Morainal\lf 29,400 10.9 0.8
222N-Lake Agassiz, Aspen Parklands\lf 3,400 1.3 0.1
\hrule
Extent Extent
in in
Province Section Area Province U.S.
\hrule
mi2 % %
M221\lf \lf 68,100 1.9
M221A-Northern Ridge and Valley\lf 32,100 47.1 0.9
M221B-Allegheny Mountains\lf 9,500 14.0 0.3
M221C-Northern Cumberland Mountains\lf 5,500 8.1 0.1
M221D-Blue Ridge Mountains\lf 21,000 30.8 0.6
M222\lf M222A-Boston Mountains\lf 6,400 0.2
231\lf \lf 193,000 5.4
231A-Southern Appalachian Piedmont\lf 73,200 37.9 2.0
231B-Coastal Plains, Middle\lf 56,900 29.5 1.5
231C-Southern Cumberland Plateau\lf 8,700 4.5 0.2
231D-Southern Ridge and Valley\lf 6,700 3.5 0.2
231E-Mid Coastal Plains, Western\lf 37,700 19.5 1.0
231F-Eastern Gulf Prairies and Marshes\lf 2,200 1.2 0.1
231G-Arkansas Valley\lf 7,600 3.9 0.2
232\lf \lf 173,800 4.8
232A-Middle Atlantic Coastal Plain\lf 17,800 10.2 0.5
232B-Coastal Plains and Flatwoods, Lower\lf 86,800 50.0 2.4
232C-Atlantic Coastal Flatlands\lf 23,300 13.4 0.6
232D-Florida Coastal Lowlands (Western)\lf 12,900 7.4 0.4
232E-Louisiana Coast Prairies and Marshes\lf 13,700 7.9 0.4
232F-Coastal Plains and Flatwoods, Western Gulf\lf 13,000 7.5 0.3
232G-Florida Coastal Lowlands (Eastern)\lf 6,300 3.6 0.2
234\lf 234A-Mississippi Alluvial Basin\lf 44,300 1.2
M231\lf M231A-Ouachita Mountains\lf 8,800 0.2
242\lf 242A-Willamette Valley and Puget Trough\lf 14,900 0.4
M242\lf \lf 53,400 1.5
M242A-Oregon and Washington Coast Ranges\lf 15,700 29.4 0.5
M242B-Western Cascades\lf 15,400 28.8 0.4
M242C-Eastern Cascades\lf 22,300 41.8 0.6
M244\lf \lf 40,000 1.1
M244A-Chugach-St. Elias Mountains\lf 27,000 67.5 0.7
M244B-Lynn Canal\lf 5,900 14.7 0.2
M244C-Boundary Range\lf 7,100 17.8 0.2
M245\lf \lf 23,900 0.7
M245A-Northern Gulf\lf 7,400 30.9 0.2
M245B-Northern Alexander Archipelago\lf 5,800 24.3 0.2
M245C-Southern Alexander Archipelago\lf 10,700 44.8 0.3
\hrule
Extent Extent
in in
Province Section Area Province U.S.
\hrule
mi2 % %
251\lf \lf 218,200 6.1
251A-Red River Valley\lf 18,300 8.4 0.5
251B-North-Central Glaciated Plains\lf 51,400 23.6 1.4
251C-Central Dissected Till Plains\lf 67,900 31.1 1.9
251D-Central Till Plains\lf 36,100 16.5 1.0
251E-Osage Plains\lf 18,100 8.3 0.5
251F-Flint Hills\lf 17,000 7.8 0.5
251G-Central Loess Plains\lf 9,400 4.3 0.3
255\lf \lf 80,100 2.2
255A-Cross Timbers and Prairie\lf 35,900 44.8 1.0
255B-Blackland Prairies\lf 13,200 16.5 0.4
255C-Oak Woods and Prairies\lf 21,900 27.3 0.6
255D-Central Gulf Prairies and Marshes\lf 9,100 11.4 0.2
261\lf \lf 10,300 0.3
261A-Central California Coast\lf 5,500 53.4 0.2
261B-Southern California Coast\lf 4,800 46.6 0.1
262\lf 262A-Great Valley\lf 19,200 0.5
263\lf 263A-Northern California Coast\lf 4,600 0.1
M261\lf \lf 68,300 1.9
M261A-Klamath Mountains\lf 16,100 23.6 0.4
M261B-Northern California Coast Ranges\lf 6,300 9.2 0.2
M261C-Northern California Interior Coast Ranges\lf 2,700 4.0 0.1
M261D-Southern Cascades\lf 6,300 9.2 0.2
M261E-Sierra Nevada\lf 18,200 26.6 0.5
M261F-Sierra Nevada Foothills\lf 8,900 13.0 0.2
M261G-Modoc Plateau\lf 9,800 14.4 0.3
M262\lf \lf 24,900 0.7
M262A-Central California Coast Ranges\lf 12,400 49.8 0.3
M262B-Southern California Mountains and Valleys\lf 12 500 50.2 0.4
311\lf 311A-Redbed Plains\lf 17,600 0.5
313\lf \lf 75,300 2.1
313A-Grand Canyon\lf 22,900 30.4 0.6
313B-Navajo Canyonlands\lf 21,900 29.1 0.6
313C-Tonto Transition\lf 17,400 23.1 0.5
313D-Painted Desert\lf 9,600 12.8 0.3
313E-Central Rio Grande Intermontane\lf 3,500 4.6 0.1
\hrule
Extent Extent
in in
Province Section Area Province U.S.
\hrule
mi2 % %
315\lf \lf 160,900 4.5
315A-Pecos Valley\lf 19,400 12.0 0.5
315B-Texas High Plains\lf 48,400 30.1 1.4
315C-Rolling Plains\lf 38,800 24.1 1.1
315D-Edwards Plateau\lf 21,900 13.6 0.6
315E-Rio Grande Plain\lf 29,700 18.5 0.8
315F-Southern Gulf Prairies and Marshes\lf 2,700 1.7 0.1
M313\lf \lf 50,200 1.4
M313A-White Mountain-San Francisco Peaks-Mogollon
Rim\lf 35,100 69.9 1.0
M313B-Sacramento-Manzano Mountain\lf 15,100 30.1 0.4
321\lf \lf 85,200 2.4
321A-Basin and Range\lf 72,900 85.6 2.0
321B-Stockton Plateau\lf 12,300 14.4 0.4
322\lf \lf 87,700 2.4
322A-Mojave Desert\lf 44,200 50.4 1.2
322B-Sonoran Desert\lf 38,700 44.1 1.1
322C-Colorado Desert\lf 4,800 5.5 0.1
331\lf \lf 290,700 8.1
331A-Palouse Prairie\lf 6,600 2.3 0.2
331B-Southern High Plains\lf 17,000 5.8 0.5
331C-Central High Tablelands\lf 25,700 8.8 0.7
331D-Northwestern Glaciated Plains\lf 40,700 14.0 1.1
331E-Northern Glaciated Plains\lf 26,900 9.3 0.7
331F-Northwestern Great Plains\lf 76,100 26.2 2.1
331G-Powder River Basin\lf 45,000 15.5 1.3
331H-Central High Plains\lf 23,300 8.0 0.6
331I-Arkansas Tablelands\lf 23,400 8.0 0.7
331J-Northern Rio Grande Basin\lf 6,000 2.1 0.2
332\lf \lf 134,000 3.7
332A-Northeastern Glaciated Plains\lf 27,900 20.8 0.8
332B-Western Glaciated Plains\lf 11,600 8.6 0.3
332C-Nebraska Sand Hills\lf 18,700 14.0 0.5
332D-North-Central Great Plains\lf 16,700 12.5 0.5
332E-South-Central Great Plains\lf 59,100 44.1 1.6
M331\lf \lf 102,300 2.8
M331A-Yellowstone Highlands\lf 13,400 13.1 0.4
M331B-Bighorn Mountains\lf 5,200 5.1 0.1
M331D-Overthrust Mountains\lf 17,900 17.5 0.5
M331E-Uinta Mountains\lf 7,400 7.2 0.2
M331F-Southern Parks and Rocky Mountain Ranges\lf 7,400 7.2 0.2
M331G-South-Central Highlands\lf 17,900 17.5 0.5
M331H-North-Central Highlands and Rocky Mountain\lf 12,100 11.8 0.3
M331I-Northern Parks and Ranges\lf 18,000 17.6 0.5
M331J-Wind River Mountain\lf 3,000 3.0 0.1
\hrule
Extent Extent
in in
Province Section Area Province U.S.
\hrule
mi2 % %
M332\lf \lf 81,800 2.3
M332A-Idaho Batholith\lf 16,800 20.5 0.5
M332B-Bitterroot Valley\lf 7,500 9.2 0.2
M332C-Rocky Mountain Front\lf 2,700 3.3 0.1
M332D-Belt Mountains\lf 12,200 14.9 0.3
M332E-Beaverhead Mountains\lf 19,600 24.0 0.5
M332F-Challis Volcanics\lf 5,600 6.8 0.2
M332G-Blue Mountains\lf 17,400 21.3 0.5
M333\lf \lf 38,100 1.1
M333A-Okanogan Highlands\lf 13,000 34.1 0.4
M333B-Flathead Valley\lf 8,200 21.5 0.2
M333C-Northern Rockies\lf 4,100 10.8 0.1
M333D-Bitterroot Mountains\lf 12,800 33.6 0.4
M334\lf M334A-Black Hills\lf 3,700 0.1
341\lf \lf 107,100 3.0
341A-Bonneville Basin\lf 25,600 23.9 0.7
341B-Northern Canyon Lands\lf 15,200 14.2 0.4
341C-Uinta Basin\lf 3,500 3.3 0.1
341D-Mono\lf 10,000 9.3 0.3
341E-Lahontan Basin\lf 25,500 23.8 0.7
341F-Southeastern Great Basin\lf 14,600 13.6 0.4
341G-Northeastern Great Basin\lf 12,700 11.9 0.4
342\lf \lf 159,100 4.4
342A-Bighorn Basin\lf 7,600 4.8 0.2
342B-Northwestern Basin and Range\lf 44,500 28.0 1.2
342C-Owyhee Uplands\lf 28,700 18.0 0.8
342D-Snake River Basalts\lf 10,300 6.5 0.3
342E-Bear Lake\lf 3,100 1.9 0.1
342F-Central Basin and Hills\lf 15,700 9.9 0.4
342G-Green River Basin\lf 19,600 12.3 0.6
342H-High Lava Plains\lf 8,200 5.1 0.2
342I-Columbia Basin\lf 21,400 13.5 0.6
M341\lf \lf 43,600 1.2
M341A-Central Great Basin Mountains\lf 24,400 56.0 0.7
M341B-Tavaputs Plateau\lf 7,000 16.0 0.2
M341C-Utah High Plateaus and Mountains\lf 12,200 28.0 0.3
411\lf 411A-Everglades\lf 7,800 0.2
M411\lf M411A-Dry-Humid Mountains\lf 3,700 0.1
M423\lf M423A-Hawaiian Islands\lf 6,500 0.2
\hrule
TOTAL 3,592,800
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