HUC Regions

  1. New England Region (64090 sq.mi.)
  2. Mid-Atlantic Region (97410 sq.mi.)
  3. South Atlantic-Gulf Region (278680 sq.mi.)
  4. Great Lakes Region (160300 sq.mi.)
  5. Ohio Region (161250 sq.mi.)
  6. Tennessee Region (40670 sq.mi.)
  7. Upper Mississippi Region (179530 sq.mi.)
  8. Lower Mississippi Region (104030 sq.mi.)
  9. Souris-Red-Rainy Region (60350 sq.mi.)
  10. Missouri Region (509547 sq.mi.)
  11. Arkansas-White-Red Region (225300 sq.mi.)
  12. Texas-Gulf Region (183140 sq.mi.)
  13. Rio Grande Region (132510 sq.mi.)
  14. Upper Colorado Region (112110 sq.mi.)
  15. Lower Colorado Region (139130 sq.mi.)
  16. Great Basin Region (140110 sq.mi.)
  17. Pacific Northwest Region (277660 sq.mi.)
  18. California Region (144050 sq.mi.)
  19. Alaska Region (583490 sq.mi.)
  20. Hawaii Region (6477 sq.mi.)
  21. Caribbean Region (4263 sq.mi.)