Homeward Bound

Winter is a busy season as many folks set out for ski destinations and head home for holidays. An estimated 115 million Americans traveled at least 50 miles during the final week of 2023, according to AAA, but this distance pales in comparison to the journeys made by wildlife in Greater Yellowstone. Some mule deer populations in Grand Teton National Park, for example, travel nearly three times that far to reach their winter ranges, crossing high mountain passes, rivers, highways and grasslands over a patchwork of public and private lands. A new film is now illuminating these impressive migratory feats.

The Wyoming Migration Initiative at the University of Wyoming in November released the documentary Animal Trails: Rediscovering Grand Teton Migrations, which details how Grand Teton’s mule deer migrate to lower elevations during the region’s harsh winter season. The crew documenting the muleys’ complex migratory behavior was filming in Grand Teton National Park last winter when a particularly frigid weather pattern swept the area. By that time, however, the mule deer were long gone.

“When we were filming in the Tetons, with how cold and snowy it was—three or four feet of snow—you could really see how desperately the animals would need other habitats where they could spend the winter,” director Greg Nickerson told Mountain Journal. “That really hit home for us.”

The project began as a brainstorming session for a visitor’s center exhibit requested by the park’s superintendent Palmer "Chip" Jenkins, Jr. Ultimately, the Wyoming Migration Initiative saw an opportunity to delve into mule deer migration while highlighting the various collaborative efforts that go into tracking and sustaining migratory behavior in and around the ecosystem.

A number of groups and agencies are involved in mule deer migration in the area, including the National Park Service, numerous Indigenous nations, Wyoming state agencies, and private landowners. The film includes interviews with speakers that reflect this intricate network of stakeholders and decision-makers. As it turns out, wildlife isn’t privy to the borders laid out by these various groups. Mule deer have used the same migration routes for centuries, but as human populations in the region increase, so do the obstacles the deer face in reaching their winter ranges.

Grand Teton National Park began tracking mule deer migration in 2013 using GPS collars and found that the deer disperse in multiple directions away from the park in winter. Deer cross the Tetons into eastern Idaho, heading east to Cody, Wyoming, or, like intrepid Deer 255, travel nearly 250 miles south into Wyoming’s Red Desert. According to the U.S. Geological Survey, Deer 255 holds the longest documented land migration in the Lower 48 for any species, and second on the continent only to caribou.

This migratory feat is highlighted by one of the film’s speakers, George Abeyta, a native educator from the Eastern Shoshone whose voice both opens and closes the documentary. Abeyta’s recent ancestors lived on the land that is now Grand Teton National Park.

“The ancient migration trails led to our hunting trails,” Abeyta explains in the film. “Now, they are superhighways we travel today.”

By mapping out deer migration routes, biologists can see just how many human boundaries the animals must cross to get to their various winter habitats, which Nickerson says is a crucial step in conserving migratory paths.

“These migrations cross three or four different federal jurisdictions and the Wind River Indian Reservation, and … hundreds of different private land parcels,” said the director, who has worked as a documentary filmmaker since 2008 and a writer since 2010. “Getting all those different players into alignment is really difficult unless you can look at the migration on a map and start to realize your individual jurisdictions’ contribution to the larger picture.”

More than 3 million people visit Grand Teton National Park annually, and most come between May and October, the warmer months when deer and other iconic wildlife spend their time in the park. Nickerson recognizes how easy it is to forget the rest of the year when these animals traverse hundreds of miles across rugged terrain and man-made barriers just to stay alive.

The film wrangles the intricate topic of migration into an eye-opening storyline that serves as a welcome reminder: many species that define Greater Yellowstone rely on migration routes that have grown harder to navigate due to human obstructions.

“We asked all these different people, ‘What do you want? Why do you care about this?’” Nickerson said. “They all said basically the same thing: it's for future generations to be able to appreciate wildlife and enjoy it the way we have it today. In this country, we really have an opportunity to see that vision through.”