The MariBell Transmission Project is an approximately 140-mile, 765/161-kV proposed double-circuit transmission line that would be built between Marion, Minn., and Bell Center, Wis. The proposed transmission line would span portions of Olmsted, Mower, Fillmore and Houston counties in Minnesota and Vernon and Crawford counties in Wisconsin.

The segment is part of a larger North Rochester – Columbia transmission project that was approved by the Midcontinent Independent System Operator (MISO) in December 2024. As part of the larger project, the MariBell Transmission Project will enhance the reliability and resilience of the regional electric grid, help meet surging energy demand and support the region’s growing economy.

In December 2024, MISO identified and approved a portfolio of transmission projects in its Long Range Transmission Plan that are needed to enable the grid of the future -- boosting reliability, providing access to low-cost energy resources and meeting growing energy demand. The MariBell segment is among the projects included in the plan.

MISO is the regional grid operator responsible for ensuring power flows reliably across 15 states in the central United States and the Canadian province of Manitoba.

Overall, the proposed transmission project would strengthen the ability to transfer power between Minnesota and Wisconsin, unlock access to more energy resources and enable a reliable grid for the future.

The Gopher to Badger Link transmission line project is being proposed to deliver reliable power to homes, farms and businesses across the region. This project will strengthen the electric grid and facilitate access to new energy sources. Dairyland Power Cooperative and Xcel Energy will develop separate segments of this new 765/161 kilovolt (kV) transmission line, which will run from eastern Minnesota to the Mississippi River.

Xcel Energy is developing approximately 35 miles of a new single-circuit 765 kV transmission line that will run from the North Rochester Substation near Pine Island to Marion, Minn. Dairyland Power Cooperative and GridLiance Heartland are developing the MariBell segment of the project, which will extend from Marion, Minn. to the Mississippi River. This segment will replace an existing 161 kV transmission line with a new 765/161 kV double-circuit transmission line.

MISO selected Dairyland Power Cooperative to build, operate and maintain the MariBell Transmission Project. Dairyland and GridLiance Heartland, LLC will jointly develop and construct the transmission line.

The MariBell Transmission Project will reinforce the electric grid in the Upper Midwest and enable access to low-cost energy to communities throughout the region.

The project is expected to provide numerous benefits to communities throughout the Upper Midwest, including enhancing the reliability of the regional grid and unlocking access to more energy resources. In addition, the project would help support the region’s growing economy and spur economic investment in the community during construction. The project is expected to generate approximately $380 million* in local and state tax revenue in Minnesota and state revenue in Wisconsin over the life of the project that could support community services and public infrastructure.

The proposed MariBell project is part of MISO’s focus on building a 765-kV ‘backbone’ across the Midwest that would improve access to remote energy resources to power homes, farms and business throughout the region. 765-kV transmission lines efficiently transmit electricity across long distances, maximizing the efficient use of land. In addition, one 765-kV line carries as much electrical capabilities as six 345-kV lines, minimizing the land needed by as much as 70% to 80%.

Dairyland and GridLiance Heartland are working with relevant federal, state and local regulatory agencies to ensure the project is designed, constructed and operated in compliance with applicable laws, regulations and management policies. 

We conduct rigorous environmental analyses to ensure we appropriately locate transmission lines and implement best practices to limit our impact on wildlife, sensitive habitats and other natural resources as well as Tribal, cultural and historic resources. We incorporate siting and design features to minimize impacts to sensitive viewsheds to the greatest extent practicable.

Dairyland and GridLiance Heartland intend to use existing rights-of-way where transmission assets are currently located as much as possible and expand the existing rights-of-way, as required to meet state or federal standards. We plan to work closely with communities and landowners to gather their input to limit impacts on farmland and other properties.

We are studying potential routes to identify a preferred route. The public will have an opportunity to provide feedback through the project website, at open houses and through the permitting processes of the Minnesota Public Utilities Commission and the Public Service Commission of Wisconsin.

The MariBell Transmission Project is anticipated to be in service by 2034 following the regulatory review process and thorough stakeholder and community engagement. The project schedule is subject to change.

Federal and state permits and approvals, including environmental permits, will be required to support construction of the line.

We anticipate filing permit applications that include a proposed route with the Minnesota Public Utilities Commission and preferred and alternative routes with the Public Service Commission of Wisconsin in 2026. After independent analyses and public input, the Minnesota Public Utilities Commission and Public Service Commission of Wisconsin will issue the final decision on the transmission line route.

The full project parameters are still being developed. We expect a right-of-way width of up to 250 feet and steel lattice structures that are between 150 and 200 feet tall.

The MariBell transmission line was identified by MISO as necessary to increase access to low-cost energy and provide greater reliability, leading to fewer power outages and disruptions as energy demand increases.

The cost of the project will be spread across all the benefiting communities in MISO’s Midwest subregion. Communities served by Dairyland, a not-for-profit, benefit from the utility’s wholesale rates that focus on covering costs rather than maximizing profit.