Pinedale – The Sublette pronghorn herd is the Cowboy state’s largest, currently numbering some 35,000 animals with a herd population objective of 48,000. In multiple studies between 2004 and 2017, nearly 600 individual pronghorn from the Sublette herd were fitted with GPS satellite tracking collars, bringing to light one of the longest intact big game migration corridors in North America. It was discovered that some pronghorn in the Sublette herd seasonally move nearly 200 miles between summer ranges in Grand Teton National Park and winter ranges north of Rock Springs.
With the large number of animals that have been collared over the years, the dataset for the Sublette herd is very robust. However, wildlife managers and researchers also felt that the number of data points in the southern portion of this large herd could be bolstered. Given that, in March, a professional wildlife capture crew contracted by the Wyoming Game and Fish Department captured and collared 19 pronghorn in locations near LaBarge and Farson. The plan calls for an additional 60 pronghorn to be fitted with GPS collars in the coming winter of 2020-2021.
These new, collared animals will provide the fine-scale location data needed to not only delineate migration routes, but also reveal important stopover areas where animals stock up on nutrients along the way. The data will also inform managers on where to locate local conservation measures such as fence modifications and improved highway wildlife crossings.
The Wyoming Game and Fish Department is currently initiating the process of officially designating the Sublette pronghorn migration corridor while this additional movement data is being collected. As per Governor Gordon’s recently signed Executive Order, there will be several steps of public review to achieve designation of the migration corridor, including review of a biological risk assessment that will be completed for the herd and then forwarded to the Governor who will make the final designation decision.