On June 25, Western Minnesota Municipal Power Agency, represented through its agent Missouri River Energy Services, and Otter Tail Power Company received a written order from the Minnesota Public Utilities Commission approving a route permit for the Big Stone South to Alexandria 345-kilovolt transmission line.
BSSA will connect Otter Tail Power’s existing substation near Big Stone City, South Dakota, with MRES’ existing substation near Alexandria, Minnesota.
Otter Tail Power is leading development and construction of the BSSA transmission line.
"Strengthening the transmission system increases resiliency to extreme weather and helps restore power faster when outages do occur. Reliable power requires responsible, long-range planning — not just maintaining infrastructure but improving it," MRES noted in a news release.
The utilities will co-own the approximately 96-mile transmission line, strengthening the regional grid while supporting reliable, cost-effective electricity to their customers.
“This is a significant milestone as new infrastructure takes years to plan, permit, and build, and we appreciate the Commission’s approval of the Route Permit,” said the companies. “Reliability isn’t built through engineering alone. It’s built through accountability, experience, and a proven track record of keeping people informed, respecting landowners, and working through a transparent, regulated process. This investment helps us continue to meet growing energy needs while maintaining a reliable, resilient energy grid for our customers and the region.”
Otter Tail Power and WMMPA received a Certificate of Need from the PUC in October 2024, confirming the line is necessary and appropriately sized, timed, and designed. In January 2025, the South Dakota Public Utilities Commission approved a Facility Permit for the approximately 3.5-mile portion in South Dakota.
Right-of-way agents will work with landowners along the approved route to establish easements and determine structure locations.
Construction is expected to begin in 2028 and the in-service date target is by the end of 2030.
MRES is an organization of 61 member municipalities in Iowa, Minnesota, North Dakota, and South Dakota that own and operate their own electric distribution systems. MRES is governed by a 13-member board of directors who are elected by and from the ranks of our member representatives.
WMMPA was incorporated on June 16, 1976, as a municipal corporation and political subdivision of the State of Minnesota.
WMMPA has a formal relationship through which WMMPA finances the construction and acquisition of the generation and transmission facilities for members of MRES.
MRES staff provides the administrative services to manage WMMPA's portfolios. WMMPA's membership primarily includes the Minnesota members of MRES.
