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Sentinel is the weapon system proposed to replace the aging Minuteman III intercontinental ballistic missile system. It represents the modernization of the land-based leg of the U.S. nuclear triad and would extend its capabilities through 2075.
On-Base Construction
Missile Alert Facilities and Launch Facilities
Utility Corridors
Communication Towers
Temporary Workforce Hubs and Centralized Laydown Areas
MMIII Decommissioning and Disposal
Construction will begin on base at F.E. Warren in the summer of 2023. Off-base survey, real estate acquisition, design investigations, and construction will begin during this same time. Work will progress from F.E. Warren AFB to Malmstrom AFB and then conclude at Minot AFB. No activities at Malmstrom or Minot AFBs are scheduled at this time. Please use the links above to find additional information about the project, the Environmental Impact Statement (EIS) completed in March 2023, and on work activities scheduled to begin in Summer 2023.
Malmstrom AFB is home to the 341st Missile Wing.
On-base actions at Malmstrom AFB would include new construction and renovation to support Sentinel command, communications, maintenance, training, and storage facilities.
Renovate 15 Missile Alert Facilities and 150 Launch Facilities
Construct 31 Communication Towers
Acquire easements to install and maintain 1,277 miles of new utility corridors
Install and maintain additional utilities within 1,750 miles of existing utility corridors
Establish 2 workforce hubs in Great Falls and Lewistown, MT
50–60 acres in size
2,500–3,000 residents during peaks for 3–5 years
Establish construction laydown/staging areas in Augusta, Belt, Denton, Judith Gap, Lewiston, Stanford, Vaughn, and Winifred, MT
About 13 acres in size
In place for 3–5 years
The Air Force contractor would coordinate with city and county officials before selecting sites for the temporary facilities and obtain permits as necessary to meet all local zoning requirements.
F.E. Warren AFB is home to the 90th Missile Wing.
On-base actions at F.E. Warren AFB and Camp Guernsey would include new construction and renovation to support Sentinel command, communications, maintenance, training, and storage facilities.
Construct 18 Communication Towers
Acquire easements to install and maintain 910 miles of new utility corridors
Install and maintain additional utilities within 1,611 miles of existing utility corridors z Establish a workforce hub in Kimball, NE
Establish construction laydown/staging areas in Albin, WY; Kimball, NE; Sidney, NE; and Stoneham, CO
Minot AFB is home to the 91st Missile Wing.
On-base actions at Minot AFB would include would include new construction and renovation to support Sentinel command, communications, maintenance, training, and storage facilities.
Construct 13 Communication Towers
Acquire easements to install and maintain 939 miles of new utility corridors
Install and maintain additional utilities within 1,531 miles of existing utility corridors
Establish a workforce hub in Minot, ND
Establish construction laydown/staging areas in Balfour, Bowbells, Garrison, Mohall, Ruso, Stanley, and Wabek, ND
On-base activities at Hill AFB would include new construction and renovation to support Sentinel maintenance, storage, and training support facilities.
On-base activities at Utah Test and Training Range would include new construction and renovation to support Sentinel maintenance, storage, and training support facilities.
The National Environmental Policy Act of 1969 (NEPA) was signed into law on January 1, 1970. NEPA is our basic national charter for protecting the environment. NEPA requires federal agencies, like the U.S. Air Force, to assess the environmental effects of their proposed actions prior to making decisions. Using the NEPA process, agencies evaluate the environmental and related social and economic effects of their proposed actions. Agencies also provide opportunities for public review and comment on those evaluations.
If a federal agency’s project or activity, like the Air Force’s deploying the Ground Based Strategic Deterrent and decommissioning and disposal of the Minuteman III, has the potential to cause significant adverse effects on the natural or human environment, NEPA requires the development of an Environmental Impact Statement (EIS). An EIS is a document that presents an in-depth analysis of the potential effects of the proposed action and its alternatives. Preparing an EIS includes opportunities for public involvement in the agency planning/decision-making processes. The document begins with a description of the baseline conditions of the affected environment. The effects of the proposed action and alternative actions are evaluated against this baseline. An EIS defines the project’s potential environmental consequences and the measures that should be taken to mitigate those effects. An EIS is used by federal and state officials, in conjunction with other relevant material, to plan actions and make decisions.
If the analysis suggests a potentially significant effect would occur from the proposed action or its alternatives, the Air Force would develop appropriate mitigation measures to offset the adverse effects. The proposed action might have significant effects that are not mitigable to less than significant.
You may visit the project website at www.gbsdeis.com. The website provides information on the project, including dates and locations of public meetings, all the materials being provided during the Draft EIS public hearings, the Draft EIS for review and comment, and methods for providing comments on the Draft EIS to the Air Force.
The final Environmental Impact Statement was released March 31, 2023; and a Record of Decision to be signed no less than 30 days after issuance of the Final EIS.
If you have questions about the Sentinel program, please email us at AFGSC.Sentinel.Hotline@us.af.mil, or call the Sentinel Hotline at (307) 773-3400.
Environmental analysis clears Sentinel missile infrastructure construction for takeoff
625th Strategic Operations Squadron lights up the night sky
USAF hosts Laramie County Sentinel town meeting
AFGSC Commander discusses mission, modernization
Minuteman III modernization effort kicks off at F.E. Warren
Air Force General Counsel visits 90MW
Updated May 25, 2023