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Sentinel (GBSD)

Shown is an illustration of the LGM-35A Sentinel launch center Shown is an illustration of the LGM-35A Sentinel Shown is an illustration of the LGM-35A Sentinel launch silo


The Sentinel, formerly known as the Ground Based Strategic Deterrent (GBSD), is the Air Force’s program to modernize the intercontinental ballistic missile system (ICBM). The Sentinel Real Estate effort will use a limited portion of privately owned property to support future infrastructure, including possible construction and maintenance of a new utility corridor or a communications tower on a portion of property. The Air Force or an authorized representative will contact private landowners to obtain access when it identifies parcels that may be needed to support the Sentinel program.

If the Air Force determines property is needed for the program, the Air Force will contact the property owner and notify them that their property is selected. The law allows the Air Force to offer fair market value for use of the property.

In order to determine the fair market value associated with a particular property, the Air Force will need a signed Right of Entry (ROE) to enter the property to do land surveys and appraisals of the portion of the property that was selected. The action of the land surveyors and appraisers will cause no damage to the property.

Once the fair market value of the property is assessed and an offer is agreed upon by both parties, a signed easement or deed will be required to finalize the transaction. An easement grants rights to use the land of another for a specific purpose for a specific term or in perpetuity and usually cannot be withdrawn during its term. Usually, property owners maintain possession and can use it so long as such use does not interfere with the purpose for which the easement was granted.

Construction should begin in the mid-2020s and be completed by the mid-2030s. As part of this program, new utility corridors are being proposed across three missile fields. Excavation corridors are also proposed adjacent to about 4,900 miles of existing Air Force easements associated with existing Minuteman III silos.

Frequently Asked Questions

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

Q1: Why does the Air Force want to access my property?

The update from Minuteman III to the Sentinel ICBMs requires upgrading existing technology launch centers and support facilities. The Air Force needs access to local property for environmental analysis, land surveys, and appraisals. In some cases, the Air Force needs access to local property to assess locations for various construction and system deployment needs.

Q2: What will my property be used for?

Your property has the potential to either be used for utility corridors, buried cables or as a location for a GBSD communications tower.

Q3: What will happen if the Air Force determines it wants to use my property?

The Air Force will reach out to you well in advance and provide detailed information regarding the desired amount and location of land to be used for the Sentinel program. After conducting an appraisal to determine the fair market value, the Air Force may offer to purchase the land (if to be used for a tower location) or to request an easement for temporary access or utility lines.

Q4. How do you determine fair market value?

Fair Market value will be determined by an independent professional real estate appraisal in accordance with appropriate state and local regulations.  The Department of the Air Force, or authorized representative, will use this real estate appraisal as a basis for establishing the value of any real estate transactions.

Q5: Why my property? Why not go around?

The Air Force has taken every step trying to avoid using more private land than is necessary for completion of the Sentinel program. After exhausting all other options, the Air Force has found that the potential use of some private property is necessary for completion of Sentinel program needs.

Q6. If I sell my land, will I be able to lease it back?

Utility corridor easements will allow you to lease the property to additional parties, so long as the Government’s right to maintain and operate a utility corridor on that property is not impacted by the leasee.

Q1: Can I continue to use the land?

Access would be limited for a short time during construction, but landowners would continue to be able to use the land after installation activities are completed.  Some restrictions pertaining to installing permanent structures may also apply. The Air Force would work with landowners regarding the timing for construction in order to minimize the impact on the owner’s use of the property.

Q2. Will farmers be able to farm their land after they allow access to their land?

Yes.  However, access will be limited during construction, but landowners can continue to use the land after installation activities are completed. For a short time during the construction and installation process, property owners will not have access to designated portion(s) of the acreage. Some restrictions pertaining to installing permanent structures may also apply.  The Air Force will work with landowners regarding the timing for construction in order to minimize the impact on the owner’s use of the property. The Air Force will restore land to a pre-existing state to the extent possible.

Q3: I currently use my property for agriculture in the area the Air Force is looking to purchase. Would advance communication allow me to harvest crops, cut grass, or move cattle from the area before work begins?

The Air Force will give advanced notice of its construction activities on the property so that landowners can plan accordingly.

Q4. What restrictions will there be on the use of my land after installation?

Landowners will not be able to install or construct permanent structures over the easement, as easy access to the easement utility corridor cabling by the Air Force is required for the future operational reasons, such as cable maintenance.  However, it is important to note that the buried utility cable should not impact ranch and farming operations.

Q5. After the project is done, what other access will I have to give the government?

It depends upon which portion of the project will be conducted on the property. For utility corridors, once the project is complete, the easement allows the Air Force the right of ingress and egress to patrol, maintain, repair, replace the utility. However, the landowner will be notified by a Government Representative that they will be on their property on a particular date and will try to de-conflict schedules to the extent possible. For tower sites, the Government will own the right to ingress and egress the tower sites with no notice to the landowner. If gates are installed to limit access to the road for whatever reason, the Government will also need to access the gate. All of this will be explained in detail to the landowners when the decision regarding the use of private property is made.

Q6. Would the Air Force use existing utility corridors and/or construct new ones?

The Air Force is proposing to use both existing utility corridors and to establish new corridors to meet Sentinel operational requirements. 

Q7. If the Air Force is not proposing to use the existing corridors, what would become of the buried cables?

All existing corridors would continue to be used.  Except in limited locations near the decommissioned Missile Alert Facilities, cables would not be abandoned in place and all existing easements would continue to be utilized.

Q8. I was asked to provide access for a corridor that has crops on the other side. Will I be able to access these fields after the corridors are dug? I don’t want to lose the crop. 

After the installation/construction of the utility corridor is accomplished and restoration activities are accepted, the property owner may continue farming operations.

Q9. Where would the antennas be located and how much land is needed for each location? Would we have to provide access to those easements through our land? Are farmers restricted from building on their land until the project is determined?

The Air Force has assessed Sentinel system requirements and has identified proposed locations of antennas and tower sites that can meet the system’s operational needs. Exact siting of roads and dimensions of pads have not been finalized and are still being planned and designed. Initial plans for tower sites would require five-acre parcels and an access road. The location of the site and road is fairly flexible as a final location is negotiated with landowners. Landowners are not restricted from developing their property in anyway until an actual easement or purchase is completed between the landowner and government. 

Q1: What is an Environmental Impact Statement or “EIS”?

The “EIS” acronym stands for “Environmental Impact Statement.” Under the National Environmental Policy Act, the Air Force is required to conduct environmental analysis for any proposed major federal action to determine the environmental impact from the proposed activities, provide the public and other stakeholders an opportunity to comment on the action and associated analyses, and to consider all reasonable alternatives, prior to making a final determination to proceed with the action. The GBSD proposal constitutes a major federal action with potentially significant environmental impacts and thus an EIS is being developed. Following completion of the EIS, anticipated in the spring of 2023, a final determination about the GBSD proposal will be made by the Secretary of the Air Force.

Q2: What happens if you find cultural or natural resources on my property?

If the Air Force determines the proposed action could significantly impact cultural or natural resources, it presents its findings and recommended mitigation measures to landowners and appropriate stakeholders. We recognize landowners are concerned about the potential impact such findings could have on use of land and agricultural operations, and the Air Force will work closely with landowners to ensure mitigation procedures – if needed – are coordinated appropriately. 

*For more information regarding the environmental impact of this project, visit

Q3: Will the frequencies transmitted from the proposed towers be harmful?

The equipment installed on the new communication towers associated with the GBSD project would be coordinated with the FCC using existing approval processes for use of the electromagnetic spectrum and installed in accordance with all applicable safety requirements.  Please refer to the FCC’s radio frequency safety site for additional information:  RF Safety FAQ | Federal Communications Commission (

Q1. When is the approximate start date of the project?

The Air Force plans to start construction in 2024.

Q2.How long is the duration of the project going to take approximately?

On-base construction would take approximately 10 years, whereas, construction throughout the missile field would take from three to five years for each missile wing. The installation of the utility corridors would take place at a rate of approximately one mile per day. The construction activities at any launch facility or missile alert facility would normally take less than a year.

Q3. Would there be standard hours of operation for the construction to happen? Should my family expect work to be occurring overnight?

All Air Force construction sites would normally have scheduled daily start and stop times, which would be shared with landowners in advance. It is possible that there would be limited 24-hour construction at some site to reduce the overall time at any one site. Any landowners living in the area of construction would be given advanced notice of construction or maintenance activities.

Q4. I noticed the Air Force also needs access to an ingress/egress route to the property. Will you be utilizing pre-existing roads, driveways, and following fence lines to access the property in a non-intrusive way? Will I be informed of your ingress/egress path in advance?

The Air Force’s goal is to minimize impact to landowners and natural resources, and we will determine the least intrusive and least destructive paths to enter and leave property. The Air Force will give advanced notice before any construction or establishing an entrance/exit route.

Q5. Would there be any project related road/highway closures?

None are planned at this time, as most road crossings of the utility corridor would be done by directional boring. It is still too early in the process to know if soil conditions are particular areas would allow for boring and if road cuts would be needed. It is likely there would be temporary lane closers and the possibly for temporary road closures during utility installations both on- and off-base.

Q6. When construction is happening will farmers still have priority on farm to market roads?

Construction requires Government officials to coordinate frequently and regularly with local officials in order to ensure farmers are coordinated with as construction impacts roadways. 

Q1. Who is the lead contractor awarded the bid?

The Department of the Air Force awarded Northrop Grumman the GBSD Engineering and Manufacturing Development contract in September, 2020.

Q2. How many contractors are going to be on this project?

The Air Force estimates the project will employ between 2,000 to 3,000 contractors during the construction phase. Overall, the GBSD program will involve nearly 10,000 people across the U.S. working directly in support of the program.

Q3. How can local businesses become partners on the project?

Small businesses interested in doing business with Northrop Grumman should complete the Supplier Information form at Suppliers - Northrop Grumman.  Completing this form will start the process and ensures Northrop Grumman and its subcontractors have good contact information for the small business and an understanding of their capabilities. 

Q4. Will the project partner with the school district and local colleges for training? 

Given the shortage of skilled trades in the region, the project will look for potential opportunities to partner with career and technical education programs at the high schools and community colleges in the area. Workforce development in the region is key to the success of the fielding of the Ground Based Strategic Deterrent.

Q5. Where will employees or workers come from? Will there be local recruitment of employees?

Due to a shortage of skilled trades in the region, many employees will come in from other areas of the country for the project.  The project is committed to hiring qualified local employees and has set a goal of hiring up to 20% (up to around 600) of project employees from local communities.  

Q6. How many people will be coming and where will they be housed?

The typical number of contract employees working on the project is anticipated to fluctuate between 2,000 - 3,000.  Most employees hired for construction of the first missile wing would be housed at a workforce hub located in Southwest Nebraska in the vicinity of the town of Kimball.  Up to 250 employees would be based in Cheyenne, Wyoming and would rely on locally available housing.  Some employees will be hired from local communities, but they will presumably already have housing. 

Q7. Where will the people be housed for the duration of the project?

Most employees (up to 3,000) will be housed in a work hub located in Southwest Nebraska.  Up to 250 employees will be based in Cheyenne, Wyoming and will rely on locally available housing.  Some employees will be hired from local communities, and they will presumably already have housing. Given the timeframe and magnitude of GBSD deployment, this answer is based on the best information currently available but is subject to change and will be updated as appropriate.

Q8. Will the presence of the work hub with up to 3,000 workers impact the number of children enrolled in schools?

The vast majority of employees associated with the Ground Based Strategic Deterrent project will not bring families with them to the area, so we believe they will have little impact on schools.  Some of the employees working directly on the project will be hired from the local area and therefore would not add any additional students to the schools.  Given the timeframe and magnitude of GBSD deployment, this answer is based on the best information currently available but is subject to change and will be updated as appropriate.

Q9. How will the Air Force keep my cattle and family safe when construction to install the cables begins? Will fencing or other safety measures be installed?

Each Air Force construction site will have a documented safety plan to protect workers and provide necessary safeguards for the surrounding environment. The Air Force will ensure landowners have the details of the plans when they are developed.

Q1. What concessions is the government willing to make to allow landowners to build wind turbines?

The GBSD program is not in a position to provide concessions to address wind turbine development.  The resources appropriated from congress only allow us to purchase easements for utility corridors and tower sites at an appraised fair market value.  Federal Appropriation Law restricts exceeding a fair market value.