The Mariana Islands Range Training Complex (“MIRC”) is both the name of a geographic area containing a complex of military training ranges and the name of a Defense Department project, originally proposed in 2007, authorizing a variety of training activities and exercises within those ranges.

In terms of geography, the MIRC included land, sea, and airspace on and around the islands of Guam, Rota, Tinian, Saipan, and Farallon de Medinilla, as well as open ocean waters stretching north to Pagan and west to the middle of the Philippine Sea.

In terms of military training activities, the MIRC included a wide variety of training within the CNMI and its waters, including, most notably, at and around Farallon de Medinilla, within Tinian’s Military Lease Area, and in certain areas of Rota used for special warfare training.

Controversially, the MIRC project codified a 10-nautical mile surface danger zone, with associated access limitations, surrounding Farallon de Medinilla. However, it also imposed important training restrictions in other sensitive locations, such as Tinian’s Unai Chulu.

MIRC was approved in 2010 and remained in effect until 2015, when it was superseded by the Mariana Islands Training and Testing Project.

Additional information about MIRC can be found here, as well as in the MIRC Field Guide and Pocket Guide developed to support enhanced understanding of the MIRC and environmental conditions and compliance considerations for this project.

The MIRC project authorized a variety of military training activities on Guam, Rota, Tinian, Saipan, and FDM; waters and airspace surrounding those islands; and open ocean waters stretching north to Pagan and west to the middle of the Philippine Sea.

Project Effects

Effects Identified as Potentially Significant in EIS

Impacts on marine mammals, sea turtles, and their habitats; soil erosion, compaction, runoff, and related issues; corals; hazardous materials and hazards; invasive species; terrestrial wildlife and habitats; cultural resources; recreation

Additional Areas of Concern

Aircraft noise; Tinian and FDM access restrictions; failure to consider impacts cumulatively with impacts of Relocation project; effectiveness of mitigation

Timeline of activities

The following timeline pinpoints important milestones for U.S. military operations and proposals in the CNMI. As shown, the U.S. military has been a part of CNMI culture and economy for many decades.


The Covenant establishing the CNMI as a U.S. Commonwealth was signed by negotiators on February 15, 1975. Section 803 required that a separate Technical Agreement Regarding Use of Land To Be Leased by the United States in the Northern Mariana Islands be executed simultaneously with the Covenant.


U.S. Department of Defense, Military Training in the Marianas Final Environmental Impact Statement and Record of Decision (June 1999)


Joint Region Marianas (JRM) was established in accordance with congressional legislation implementing the recommendations of the 2005 Base Realignment and Closure Commission.


Mariana Islands Range Complex Final Environmental Impact Statement/Overseas Environmental Impact Statement, published May 2010.

The Quadrennial Defense Review (QDR) evaluated global U.S. military strategy and priorities (Department of Defense 2010, CNMIJointMilitaryTrainingEIS.com), and called for development of additional training capabilities for unit, combined, and joint forces in the Western Pacific.

Guam and CNMI Military Relocation Final Environmental Impact Statement: Relocating Marines from Okinawa, Visiting Aircraft Carrier Berthing, and Army Air and Missile Defense Task Force Volume 3, published in July 2010


Training Needs Assessment: An Assessment of Current Training Ranges and Supporting Facilities in the U.S. Pacific Command Area of Responsibility (hereafter the “Assessment”) identified and validated unfilled training requirements for units/commands in the U.S. Pacific Command Area of Responsibility (Department of the , 2013, CNMIJointMilitaryTrainingEIS.com.


Mariana Islands Range Complex Airspace Environmental Assessment/Overseas Environmental Assessment, published in June 2013.


The 2014 QDR confirmed the U.S. military’s continued commitment to rebalance the Asia-Pacific region, which is increasingly central to U.S. political, economic and security interests.


Record of Decision for the Final Supplemental Environmental Impact Statement for Guam and Commonwealth of the Northern Mariana Islands Military Relocation


U.S. Air Force (USAF) Tinian Divert Infrastructure Improvements Supplemental Environmental Impact Statement (SEIS)

Mariana Islands Training and Testing SEIS/Overseas EIS, published June 2020

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