Project Information

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.

Project Information

On-Base Construction

Construct or modify facilities and infrastructure as necessary to support Sentinel maintenance, training, storage, testing, and support at F.E. Warren Air Force Base (AFB), Malmstrom AFB, Minot AFB, Hill AFB, the Utah Test and Training Range (UTTR), and Camp Guernsey.

Missile Alert Facilities and Launch Facilities

Demolish all 45 missile alert facilities (MAFs) in the missile fields.
Construct a communication support building at each MAF location.
Construct a launch center within the property boundaries of at least 24 of the MAFs.
Renovate all 450 existing launch facilities in the missile fields to like-new condition.

Utility Corridors

Establish approximately 3,100 miles of new utility corridors.
Acquire 100 feet of temporary construction easements.
Acquire 16 feet of permanent easements to install and maintain utilities.
Place no aboveground permanent infrastructure within the easements.
Conduct activities within the 4,900 miles of existing utility corridors and easements.
Acquire temporary easements to supplement the existing easements during construction.

Communication Towers

Acquire property rights to construct 62 communication towers within the three missile fields: 18 at F.E. Warren AFB, 31 at Malmstrom AFB, and 13 at Minot AFB.
Construct 300-foot towers supported by guy wires.
Tower sites would be approximately 5 acres in size and generally be located near existing roads and utilities and avoid sensitive resources.

Temporary Workforce Hubs and Centralized Laydown Areas

Establish temporary workforce hubs for up to 2,500–3,000 employees (during peak construction periods) in the vicinity of Great Falls and Lewistown, MT; Kimball, NE; and Minot, ND.
Establish temporary construction laydown areas of about 13 acres throughout the missile fields.
Use workforce hubs and laydown areas for 2–5 years.

MMIII Decommissioning and Disposal

Remove, decommission, and dispose of the MMIII weapon system and associated facilities at F.E. Warren AFB, Malmstrom AFB, Minot AFB, Hill AFB, UTTR, and Camp Navajo.

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 https://www.afgsc.af.mil/Sentinel-GBSD/ 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.

Below are some frequently asked questions to help you better understand various aspects of the Sentinel program.

Hill AFB

On-base activities at Hill AFB would include new construction and renovation to support Sentinel maintenance, storage, and training support facilities.

National Environmental Policy Act

What is NEPA?
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.
What is an EIS?
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.

The final Environmental Impact Statement was released March 31, 2023; and a Record of Decision was signed on May 19, 2023, by Robert Moriarty, Deputy Assistant Secretary of the Air Force for Installations.

The record of decision, or “ROD,” details the findings of the Air Force’s analysis of environmental, natural resource and cultural considerations in the construction of the Sentinel intercontinental ballistic missile project. The document identifies the selected course of action and basis for the decision and provides information on how the Air Force intends to avoid, minimize or mitigate environmental impacts throughout the life of the project, to the maximum extent possible. Read more here.
What if the analysis in the EIS shows there will be a significant adverse effect?
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.

The final Environmental Impact Statement was released March 31, 2023; and a Record of Decision was signed on May 19, 2023, by Robert Moriarty, Deputy Assistant Secretary of the Air Force for Installations.

The record of decision, or “ROD,” details the findings of the Air Force’s analysis of environmental, natural resource and cultural considerations in the construction of the Sentinel intercontinental ballistic missile project. The document identifies the selected course of action and basis for the decision and provides information on how the Air Force intends to avoid, minimize or mitigate environmental impacts throughout the life of the project, to the maximum extent possible. Read more here.
Where can I receive additional information or stay informed on the progress of the EIS?
You may visit the project website at https://www.afgsc.af.mil/Sentinel-GBSD/. The website provides information on the project, including dates and locations of public meetings, copies of the draft and final Environmental Impact Statement, locations, a FAQ, contact information, and more.
When do you expect the EIS to be complete and the final decision made?
The final Environmental Impact Statement was released March 31, 2023; and a Record of Decision was signed on May 19, 2023, by Robert Moriarty, Deputy Assistant Secretary of the Air Force for Installations.

The record of decision, or “ROD,” details the findings of the Air Force’s analysis of environmental, natural resource and cultural considerations in the construction of the Sentinel intercontinental ballistic missile project. The document identifies the selected course of action and basis for the decision and provides information on how the Air Force intends to avoid, minimize or mitigate environmental impacts throughout the life of the project, to the maximum extent possible. Read more here.

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.