Gov. Mark Gordon announced the designation of the Sublette Antelope Migration Corridor on Friday afternoon. The migration route spans from the Tetons to the Red Desert. It is the longest antelope migration corridor in the continental U.S.
The designation through executive order guides how future development can happen within the corridor.
According to the Wyoming Outdoor Council, new project proposals on public and state land within the corridor will have to be approved by Wyoming Game and Fish. Also, surface disturbance and certain human activities will be prohibited in bottlenecks, and other restrictions can be imposed in high-use portions of the corridor.
This decision follows a recommendations report submitted by the Sublette Anetelop Local Working Group and is the culmination of a yearslong process.
The designation was spelled out in a 2020 executive order, which intended to delineate pronghorn and mule deer corridors and potentially add buffers from development if there are threats, while also still allowing most energy development and agricultural uses to continue.
The Sublette pronghorn herd was essentially the guinea pig. Officials homed in on the herd after a 2024 Wyoming Game and Fish Department (WGFD) study showed the herd’s route was at “high risk” of being lost. Specifically, it pointed to housing and energy development, as well as a devastating winter that slashed the herd of about 40,000 members to a shocking 20,000.
WGFD commissioners ultimately sided with those threats and the public’s strong urging at a September 2025 meeting when they recommended the full designation of the entire route to the governor. That’s 10 segments, including the Red Desert and the east of Farson segments.
In December, the governor proposed dropping energy development protections for parts of the route, siding with state wildlife biologists by nixing two sections: the Red Desert and the east of Farson areas.
At the same time, Gordon appointed a local working group to review WGFD’s risk assessment and propose a final recommendation.
That group spent the last six months studying and developing the report that ultimately supported the designation of eight corridor segments, including 12 bottleneck areas. It does not include the Red Desert and the east of Farson segments. The working group also recommended adjusting development timing on a case by case basis at the discretion of WGFD and asking the governor to consider establishing a Memorandum of Understanding between the WGFD, the Bureau of Land Management and the regional U.S. Forest Service to work together on conserving the corridor.
In addition to the Sublette Antelope Corridor, Gordon has designated three mule deer corridors – Sublette, Baggs, and Platte Valley. A fourth mule deer corridor, Wind River, is identified.
