Region

Province code

Province name

Region 1. Alaska

1

Northern Alaska

2

Central Alaska

3

Southern Alaska

Region 2. Pacific Coast

4

Western Oregon-Washington

5

Eastern Oregon-Washington

6*

Klamath-Sierra Nevada

7

Northern Coastal

8

Sonoma-Livermore Basin

9

Sacramento Basin

10

San Joaquin Basin

11

Central Coast

12

Santa Maria Basin

13

Ventura Basin

14

Los Angeles Basin

15*

San Diego-Oceanside

16*

Salton Trough

Region 3. Colorado Plateau and Basin and Range

17

Idaho-Snake River Downwarp

18

Western Great Basin

19

Eastern Great Basin

20

Uinta-Piceance Basin

21

Paradox Basin

22

San Juan Basin

23

Albuquerque-Santa Fe Rift

24

Northern Arizona

25

Southern Arizona-Southwestern New Mexico

26*

South-Central New Mexico

Region 4. Rocky Mountains and Northern Great Plains

27

Montana Thrust Belt

28

North-Central Montana

29

Southwest Montana

31

Williston Basin

32*

Sioux Arch

33

Powder River Basin

34

Big Horn Basin

35

Wind River Basin

36

Wyoming Thrust Belt

37

Southwestern Wyoming

38

Park Basins

39

Denver Basin

40

Las Animas Arch

41

Raton Basin-Sierra Grane Uplift

Region 5. West Texas and Eastern New Mexico

42*

Pedernal Uplift

43

Palo Duro Basin

44

Permian Basin

45

Bend Arch-Fort Worth Basin

46

Marathon Thrust Belt

Region 6. Gulf Coast

47

Western Gulf

48*

East Texas Basin

49

Louisiana-Mississippi Salt Basins

50

Florida Peninsula

Region 7. Midcontinent

51

Superior

52*

Iowa Shelf

53

Cambridge Arch-Central Kansas Uplift

54*

Salina Basin

55

Nemaha Uplift

56

Forest City Basin

57*

Ozark Uplift

58

Anadarko Basin

59

Sedgwick Basin

60

Cherokee Basin

61

Southern Oklahoma

62

Arkoma Basin

Region 8. Eastern

63

Michigan Basin

64

Illinois Basin

65

Black Warrior Basin

66

Cincinnati Arch

67

Appalachian Basin

68

Blue Ridge Thrust Belt

69

Piedmont

71

Adirondack Uplift

72

New England