Powered by ZigaForm version

The Last Mile Transmission Project

Innergex, through its affiliate Last Mile Transmission, LLC, is proposing a 34.5 mile 230 kilovolt transmission line running largely east-west between PacifiCorp’s existing Freezeout Substation in Carbon County, WY, northeast of Medicine Bow and the proposed Boswell Springs substation approximately 14 miles northeast of Rock River in Albany County. This proposed Last Mile Transmission Line Project (“Last Mile”) would cross privately-owned lands in both Carbon and Albany Counties and lands administered by the Bureau of Land Management and the State of Wyoming.

The Last Mile Transmission Project is expected to use a combination of wooden H-frame and single steel pole transmission structures with each structure being ~75-110 feet in height.

Last Mile is currently applying for a Conditional Use Permit with Carbon County; as part of this process, the Carbon County Planning & Zoning Commission will hold a public hearing on Monday, April 4, 2022, beginning at 10:00 A.M., Carbon Building, 3rd Floor-Room 332, located at 215 West Buffalo Street, Rawlins, Wyoming. After the Planning & Zoning Commission meeting, their recommendation will be forwarded to the Board of County Commissioners.

Purpose and need for the project

In 2020, PacifiCorp initiated an all-source Request for Proposals (“2020AS RFP”) to solicit competitively priced energy resources that can meet the region’s energy needs. Innergex’s proposed Boswell Springs Wind Project has been shortlisted in the 2020AS RFP and Last Mile is the transmission line that would connect the Boswell Springs Wind Project with PacifiCorp’s electrical grid. The need for this type of transmission collector system had been identified by the Wyoming Infrastructure Authority (“WIA”) and PacifiCorp. The WIA identified this target area for a transmission collector system and transmission export hub as part of the Wyoming Collector and Transmission System Conceptual Design (WIA 2010). Together, the projects bring considerable benefits to the region.

Community Benefits

Innergex’s philosophy has always been to develop and operate reliable, high-quality projects while respecting the environment and balancing the best interests of communities and partners. Thus, when developing a project, Innergex believes in maximizing local benefits, such as giving preference to hiring local people, consultants, businesses, and contractors.

In addition to construction and employment expenditures, the Last Mile Project is expected to pay $510K in sales and use taxes, distributed as $340K to the State of Wyoming, $105K to Carbon County, and $65K to Albany County.

The Project will generate increased yearly tax revenue for state and local governments from property taxes based on the Project’s assessed value, starting at an estimated $119K in 2025, once the transmission line is fully constructed. These revenues would directly benefit the State School Fund, the Carbon County General Fund, Carbon County School District #2, the Medicine Bow Health District, the Medicine Bow Conservation District and other county facilities and tax districts.


Siting considerations

Innergex evaluated nearly a dozen potential routes for the project, taking into account many significant constraints. This final design represents the shortest transmission line route possible to minimize physical and visual impacts, with several considerations including landowner interest, constructability, engineering and environment constraints, avoidance of subdivisions/towns, setbacks, etc.

The proposed project area is relatively flat and characterized by rolling plains and primarily used for grazing. This Project is very compatible with existing and future ranching and agricultural operations which can continue throughout the life of the Project, including during construction. In addition, the post-construction right-of-way would be reclaimed to the minimum footprint needed for long-term operation and maintenance of the line, maximizing the amount of land available for ranching and agricultural activities.

Development of the Last Mile Project required environmental impact analyses and studies as part of the permitting process, especially with respect to the land managed by the Bureau of Land Management (“BLM”). No BLM Areas of Critical Environmental Concern, BLM Natural Areas, or designated wilderness areas are present in the project area. The Project also avoids the Como Bluff National Natural Landmark.


About Innergex

Founded in 1990, Innergex is an independent renewable power producer which develops, constructs, acquires, owns, and operates hydroelectric, wind, solar and energy storage facilities. Innergex is a long-term owner and operator of clean energy projects located in the United States, Canada, Chile, and France. Innergex is also the owner of the proposed 332MW Boswell Springs Wind Project in Albany County.


Project funding

Innergex will be responsible for 100% of the development, financing, construction, and start-up costs. After completion, Innergex will also be responsible for all operational and maintenance costs, as well as all decommissioning costs.


The Last Mile Project has been in negotiations with private landowners and the BLM to obtain the easements/right-of- way and permits necessary to construct, own, and operate the Project and expects to complete these by early 2022. Last Mile has concluded a National Environmental Policy Act (NEPA) review with the BLM and is currently applying for a Conditional Use Permit with Carbon County; as part of this process, public hearings will be held with the Carbon County Planning and Zoning Commission and with the Board of County Commissioners.

Innergex hopes to begin construction on the Last Mile line in Q2 2023 and to be operational by Q3 2024.
The Last Mile Project will interconnect the proposed Boswell Springs Wind Project (also owned by Innergex) which has its own permitting and consultation process and are largely done independently from Last Mile.



To download the Last Mile Project Handout

To download the Application for Conditional Use Permit

Contact us

It is important to Innergex that we keep you informed as we go forward with this potential Project and to be a good community partner and neighbor. Please contact us if you have any questions or comments:


Last Mile, C/O Innergex Renewable Energy
3636 Nobel Drive, Suite 260,
San Diego, CA, 92122