Unified Interior Regional Boundaries


  • The reorganization of DOI from 49 regions across 8 bureaus to 12 unified Interior Regions is complete. Unified Interior Region boundaries - based on watersheds but generally drawn along state lines to simplify coordination with external partners - became final on August 22, 2018

  • Bureaus have amended their Department Manual chapters to officially align their regional/office boundaries with the Interior Region boundaries

  • This crosswalk of bureau regions with Interior Regions will help you identify which Interior Region you are in, and who your bureau regional executive (e.g., regional or state director) is

  • Reorganizing from 49 regions across 8 bureaus to 12 Unified Regions adds greater efficiency, accountability, collaboration and consistency across our bureaus

  • Reorganization will make joint problem-solving and improved coordination between our bureaus and local partners easier, improving the experience for the customer, whether that is a government agency, permit seeker, or landowner


Interior Region Map files for download:

Jpeg (400 KB)

PDF  (3 MB)

Shapefiles (for mapping software)

Unified Interior Regions

  • Region 1: North Atlantic-Appalachian
  • Region 2: South Atlantic-Gulf (Includes Puerto Rico and the U.S. Virgin Islands)
  • Region 3: Great Lakes
  • Region 4: Mississippi Basin
  • Region 5: Missouri Basin ​
  • Region 6: Arkansas-Rio Grande-Texas-Gulf
  • Region 7: Upper Colorado Basin
  • Region 8: Lower Colorado Basin
  • Region 9: Columbia-Pacific Northwest
  • Region 10: California-Great Basin
  • Region 11: Alaska
  • Region 12: Pacific Islands (American Samoa, Hawaii. Guam, Commonwealth of the Northern Mariana Islands)

Complexity of Managing Public Lands

The complexity of administering DOI programs has expanded dramatically over time as Congress broadened DOI’s statutory duties. As its mission and bureaus grew, so have competing interests and priorities between bureaus and offices. To fulfill DOI’s diverse purpose, we manage:  

  • 530 Million Acres – Surface
  • 700 Million Acres – Subsurface minerals
  • 2.5 Billion Acres – Outer Continental Shelf 
  • 25 million Acre-Feet of water supply 
  • 2,400 operating locations
  • 70,000 employees
  • 610,000 volunteers

Interior Region Objectives

  • Reduce administrative redundancy
  • Clarify jurisdictional and organizational barriers to citizen service
  • Facilitate resource sharing, facilitate joint problem solving, and efficient decision-making
  • Devote a greater percentage of our budget to the field
  • Improve coordination among federal, state and local agencies
  • Delegate decision making authority to the regions

Science-Based Rationale for Interior Regions

  • The unified regional boundaries are primarily based on a science-based approach to promote management efficiencies
  • We identified 12 unified Interior regions to provide better management on an ecosystem basis to include critical components such as wildlife corridors, watersheds, and trail systems. The new regional boundaries are based on watersheds. They were adjusted to follow state lines where possible based on feedback we received from Governors
  • We consulted with DOI’s career senior executive staff, Congress, governors, and external stakeholders on the most useful way to adjust the final science-based boundaries for the unified regions to ensure the boundaries are also administratively practical

Previous Region Boundaries

Map of current region boundaries



Non-DOI Bureaus and Agencies


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