The Eastern Missouri Grid Transformation Project includes more than 130 miles of new and upgraded transmission lines through Marion, Ralls, Pike, Lincoln, St. Charles and St. Louis counties, as well as the City of St. Louis.
The vast majority of the lines will be rebuilt along existing corridors and co-located with existing Ameren facilities. This project will prepare the grid for the future by replacing aging infrastructure, adding transmission capacity to ensure reliability and resiliency, and promoting more access to a balanced mix of energy sources for communities. A virtual Comment Form is available on the Interactive Map to share your feedback and sign up for the mailing list.
Interactive Map
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Anticipated Schedule
*All items shown are pending regulatory approvals. Schedule is subject to change.
Public Outreach & Stakeholder Involvement
Community leaders and members of the public will have various opportunities to provide input during each phase of the routing process as the preferred route is defined and submitted in an application for a certificate to the Missouri Public Service Commission later this year. The goal of the routing process is to identify and take advantage of opportunities while understanding and minimizing impacts to sensitivities while adhering to technical guidelines and statutory requirements.
The team will gather and review data from community members, landowners, and stakeholders during different stages of the routing process. Public outreach and stakeholder engagement will take place through a series of open houses in March 2026 to gather input on the route segments. All input received during the outreach and engagement process will be reviewed and considered, along with project routing criteria during the development of the Proposed Route.
Public collaboration remains a top priority for the project team, and community participation throughout the public engagement process is deeply appreciated. Please stay involved in the process by joining the project email and/or mailing list  to receive updates on the project in your county.
Open Houses
The Project consists of five (5) line segments, including the Maywood-Belleau line segment within Marion County. This segment upgrades the transmission line from the existing Maywood substation near Palmyra to the existing Belleau substation in O'Fallon. Specifically in Marion County, the Project involves:
- Replacement  – Replacing 18 miles of existing wood H-frame structures with new steel monopoles to carry additional energy. In most instances, the number of structures is lessened with a smaller footprint due to design and longer spans. New structures will typically be constructed within existing corridors.
- New Corridor  – Up to 2 miles of the new transmission line may be re-routed in a new corridor through the county. The new structures may be constructed as double circuit with the existing 161 kV circuits being relocated along a new transmission corridor. 
The Project consists of five (5) line segments, including the Maywood-Belleau line segment within Ralls County. This segment upgrades the transmission line from the existing Maywood substation near Palmyra to the existing Belleau substation in O'Fallon. Specifically in Ralls County, the Project involves:
- Replacement – Replacing 16 miles of existing wood and steel H-frame structures with new steel monopoles to carry additional energy. In most instances, the number of structures is lessened with a smaller footprint due to design and longer spans. New structures will typically be constructed within existing corridors.
- New Corridor  – Up to 4 miles of the new transmission line may be re-routed along a new corridor through the county.
The Project consists of five (5) line segments, including the Maywood-Belleau line segment within Pike County. This segment upgrades the transmission line from the existing Maywood substation near Palmyra to the existing Belleau substation in O'Fallon. Specifically in Pike County, the Project involves:
- Replacement – Replacing 27 miles of existing wood H-frame structures with new steel monopoles to carry additional energy. In most instances, the number of structures is lessened with a smaller footprint due to design and longer spans. New structures will typically be constructed within existing corridors. 
- New Corridor  – Up to 11 miles of the new transmission line may be re-routed in new corridors through the county. The new structures may be constructed as double circuit with the existing 161 kV circuits being relocated along a new transmission corridor. 
The Project consists of five (5) line segments, including the Maywood-Belleau line segment within Lincoln County. This segment upgrades the transmission line from the existing Maywood substation near Palmyra to the existing Belleau substation in O'Fallon. Specifically in Lincoln County, the Project involves:
- Replacement – Replacing 27 miles of existing wood H-frame structures with new steel monopoles to carry additional energy. In most instances, the number of structures is lessened with a smaller footprint due to design and longer spans. New structures will typically be constructed within existing corridors. 
- New Corridor  – Up to 9 miles of new transmission line may be routed along new corridors through the county. 
The Project consists of five (5) segments, including the Maywood-Belleau, Belleau-Graus, Graus-Sioux, and Graus-Bugle segments within St. Charles County. These segments upgrade the transmission line, and specifically in St. Charles County, the Project involves:
- Replacement – Replacing 35 miles of existing wood and steel H-frame structures and lattice towers with new steel monopoles to carry additional energy. In most instances, the number of structures is lessened with a smaller footprint due to design and longer spans. New structures will typically be constructed within existing corridors.
- New Corridor  – Up to 19 miles of new transmission line may be re-routed in new corridors through the county. 
- New Substation  – A new 345 kV substation called Graus will be constructed.
The Project consists of five (5) segments, including the Graus-Bugle and Bugle-Mississippi River Crossing segments within St. Louis County and the City of St. Louis. These segments upgrade the transmission line, and specifically in St. Louis County and the City of St. Louis, the Project involves: 
- St. Louis County Replacement – Replacing 16 miles of existing steel monopoles and lattice towers with new steel monopoles to carry additional energy. In most instances, the number of structures is lessened with a smaller footprint due to design and longer spans. New structures will typically be constructed within existing corridors. A short section of transmission line near Bugle Substation may be routed in a new corridor outside of existing right-of-way. 
- City of St. Louis Replacement  – Replacing 10 miles of existing steel monopoles and lattice towers with new steel monopoles to carry additional energy. In most instances, the number of structures is lessened with a smaller footprint due to design and longer spans. New structures will typically be constructed within existing corridors. Up to 2 miles of new transmission may be re-routed along a new corridor outside of existing right-of-way. 
The Eastern Missouri Grid Transformation Project includes more than 130 miles of new and upgraded transmission lines in five (5) line segments through six (6) counties, including: Marion, Ralls, Pike, Lincoln, St. Charles and St. Louis counties, as well as the City of St. Louis.
- Marion County – Route passes near Palmyra and Hannibal and includes the Maywood-Belleau segment, and includes the existing Maywood substation that is near Palmyra in Marion County.
- Ralls County – Route passes near Hannibal, Rensselaer, and New London, and includes the Maywood-Belleau segment.
- Pike County – Route passes near Frankford, Bowling Green, Cyrene, and Eolia and includes the Maywood-Belleau segment.
- Lincoln County – Route passes near Whiteside, Okete, Brussells, and Old Monroe and includes the Maywood-Belleau segment.
- St. Charles County – Route passes through St. Paul, O’Fallon, St. Peters, and St. Charles, and passes near West Alton and Portage Des Sioux.
- Route in St. Charles County includes the Maywood-Belleau, Belleau-Graus, Graus-Sioux, and Graus-Bugle segments,
- Route in St. Charles County includes existing Maywood substation near Palmyra, existing Belleau substation in O’Fallon, existing Sioux substation, and proposed Graus substation.
- St. Louis County – Route passes through or near Florissant, Hazelwood, Berkeley, Kinloch, Bel-Ridge, St. John, Hanley Hills, Pagedale, Hillsdale, and Wellston.
- City of St. Louis – Route passes through the City of St. Louis.
Segment Locations
- Maywood-Belleau – This segment upgrades the transmission line from the existing Maywood substation near Palmyra in Marion County to the existing Belleau substation in O'Fallon in St. Charles County.
- Belleau-Graus – This segment upgrades the transmission line from the existing Belleau substation in O’Fallon to the proposed Graus substation is in St. Charles County.
- Graus-Sioux – This segment upgrades the transmission line from the existing Sioux substation to the proposed Graus substation in St. Charles County.
- Graus-Bugle – This segment upgrades the transmission line from the proposed Graus substation to the existing Bugle substation in St. Louis County.
- Bugle-Mississippi River Crossing – This segment upgrades the transmission line from the existing Bugle substation to the Mississippi River in St. Louis County.
Phone: 877.468.1823
Email: Connect@EasternMOGrid.com
Mail:Â Eastern Missouri Grid Transformation Project Attn: WSP, 701 Emerson Road, Suite 250, Creve Coeur, MO 63141Â