Standing atop a high point on The Conservation Fund's Fremont Lake property in Wyoming's Green River Valley, one can see how the topography of the land and surrounding man-made features come together to create a narrow corridor funneling down into a bottleneck just several hundred yards wide. It's almost like a land-based flume, where thousands of mule deer are forced to squeeze through each spring and fall as they migrate a one-way distance of up to 150 miles to and from their critical wintering and summering areas in western Wyoming.

Elk barrier fencing at the Fremont Lake outlet impedes mule deer migration across the property. Photo credit: Mark Elsbree.

These spectacular animals and their biannual migration is one of the truly magnificent elements of the Greater Yellowstone system—an awe-inspiring wonder of nature. The mule deer spend their lives migrating on a singular route to survive and reproduce. They spend more than 4 months of the year on the route, moving from their high-elevation summer range where they gain needed body fat down to low-elevation wintering areas where they endure Wyoming’s long, cold season. Though the mule deer have been using this Red Desert to Hoback migration route for thousands of years, researchers only just recently identified the route in 2011 after considerable time and investment. In doing so, the biologists called out several key areas along the route that are severely threatened. If these areas are cut off or lost, the research showed, it would impede seasonal animal movements, and the migration itself could be in jeopardy. 

Mule deer winter at lower elevations and return to higher elevations each spring to graze and fatten up for the next long, cold Wyoming winter. Photo credit: Joe Riis. 

The 364-acre Fremont Lake bottleneck property described above topped the priority list of threatened sites. Tucked between public lands, the lake outlet and the City of Pinedale, this privately owned property had been approved for extensive homesite subdivision and was listed for sale on the open real estate market in late 2014.  The Conservation Fund acted quickly to contact the seller’s representative, appraise the property, conduct initial due diligence and tender an offer to purchase.  Following a focused negotiation, the proposal—all cash with a quick closing—met the approval of the seller, and the Fund closed on the purchase of these incredible lands that bind the migration corridor together at a critical juncture.

The Conservation Fund's involvement in the Red Desert to Hoback mule deer migration corridor and the permanent protection of the vital Fremont Lake property was spearheaded by Luke Lynch, the Fund's long-time Wyoming State Director. Luke had a passion for the conservation of working ranchlands and for maintaining the connectivity of large animal migration routes. “This is one of the last, best migrations,” he observed for the New York Times in February 2015.  Luke previously had led the Fund's critical private land conservation efforts associated with the protection of Wyoming's heralded "Path of the Pronghorn," this nation's first federally designated wildlife corridor, where for some 6,800 years hundreds of pronghorn have migrated nearly 200 miles to and from Grand Teton National Park.  It's the longest land mammal migration route in the lower 48 states.

Tragically, Luke was killed in May 2015 in a ski mountaineering accident on Mount Moran in Grand Teton Park, but his conservation legacy lives on, in part, through the continuing work on the Fremont Lake property—lands he acquired for The Conservation Fund just weeks before his untimely passing. There at Fremont Lake, more than 3 miles of "elk barrier" fence is being removed to enhance mule deer passage through the narrow, funnel-like property. The property, now in conservation ownership, will remain forever free of subdivision and adverse development. Additional restoration and habitat improvement is also being conducted by The Conservation Fund and its partners to ensure that this key link is maintained along the critical pathway that is the Red Desert to Hoback mule deer migration corridor.


Residential development of this critical area would have severely diminished, if not entirely eliminated, this essential pathway for mule deer migration. Barrier fencing is currently being removed to further enhance ease of travel for deer through the area. Photo credit: Joe Riis. 

The Fund’s ability to work constructively with conservation partners and to act swiftly to acquire this Fremont Lake property is absolutely essential to the permanent protection of this incredible mule deer migration.  Our work—Luke’s work—will help maintain an enduring natural cycle so it too may live on for centuries to come. It is a legacy we can all be proud of.

Learn More

National Geographic video, "A Deer Migration You Have to See to Believe"