On the Move: Teton River Canyon Mule Deer

Tuesday, April 17, 2012 Teton Valley Magazine

By Molly Loomis

Teton Valley has lots of migratory residents—second-home owners who flock to the valley for relaxation and recreation; commuters who drive back and forth to jobs in Jackson Hole; migrant workers from other countries in search of better wages and opportunity—and, of course, creatures like Canada geese and sandhill cranes.

Another wildlife species garnering a growing amount of attention is the mule deer, Odocoileus hemionus—namely, a large herd of mulies that migrate each year between the Tetons and the Teton River Canyon, situated roughly twenty miles northwest of Driggs. (This is not to be confused with the canyon of Teton Creek, known locally as Teton Canyon, which is east of Driggs.)

Deer, both mulies and whitetails, are hardly an unusual sight around the valley—hunters track them every autumn and gardeners curse their uninvited browsing. But what’s noteworthy about this herd is its size and the migration corridor it utilizes.

Each fall an estimated 2,800 mule deer make their way out of the Tetons, some of the animals coming from as far away as Jackson Lake on the east side of the range. The herd descends into Idaho through the Bitch and Badger creek drainages, eventually settling on the slopes of the Teton River Canyon—an 800-foot-deep gorge—where they’ll ride out the winter on south-facing slopes, munching on exposed plants like bitterbrush, juniper, and leftover crops and forbs. The deer will also populate the canyon’s north-facing slopes, living amongst old growth Douglas fir and stands of aspen.  In low-snow years, the deer will utilize more of the canyon rim, fields, and aspen “eyebrows,” as isolated groves are known. As the weather warms, typically sometime in March or April, they’ll begin following the growth of new forbs and grasses back toward the foothills.

Matt Lucia, stewardship director at the Teton Regional Land Trust (TRLT), explains that mule deer exhibit a tremendous degree of fidelity to traditional migratory paths. Unlike elk or certain other big-game species, mule deer are unlikely to adapt when faced with blocked migratory paths, increased human disturbances, or changes in available forage. When those critical elements fail or become degraded, the deer simply don’t survive. With that in mind, the TRLT, along with other conservation organizations and agencies—like the Rocky Mountain Elk Foundation and the Idaho Department of Fish and Game—are keeping a close eye on proposed development in the migration corridor and on the rim of the Teton River Canyon.

Hollie Miyasaki, regional wildlife biologist with the Idaho Department of Fish and Game (IDFG), has spent the past four years studying the Teton herd. “If you prevent them from getting to someplace where they can [feed during] winter, it’s going to be really hard for them to survive year to year,” she says. “So, these corridors are really important to mule deer. They’re not going to find someplace new.”

Fellow IDFG biologist Rob Cavallaro calls the mule deer a “catalyst for conservation”— a species whose preservation benefits the survival of many others. In the case of the Teton River Canyon, Columbian sharp-tailed grouse, flammulated owls, nesting eagles, Townsend’s big-eared bats, and Yellowstone cutthroat trout are all species that benefit from healthy habitat along this stunning section of river.

Luckily, to date, the Teton River Canyon and the migratory corridor through Bitch and Badger creeks are all in relatively good shape, especially when compared to terrain in the Big Hole Range and south of Victor—land utilized by the valley’s other herds (domestic, that is). But it could have gone the other way. In 2007, at the height of the building boom, a thousand acres of rolling farmland in this area were put on the market. These farm fields support crops of potatoes, barley, and alfalfa, and have interspersed among them CRP (Conservation Reserve Program) acreages and aspen eyebrows. This land runs right up to the rim of the Teton River Canyon.

Cavallaro, who at the time was the TRLT’s stewardship director, recalls how overnight the situation changed. “That wasn’t the front lines [before the building boom],” he says. “And all of a sudden, there was a new planning front.”

While many hunters believe the biggest threat to the mule deer population is increasing numbers of wolves and mountain lions, regional scientists assert that a decline in habitat quality, in migration corridors, and in winter and summer range constitutes the biggest potential obstacle to the herd’s survival. And suddenly, in the mid- to late 2000s, the Teton River Canyon mule deer population was faced with the prospect of housing developments springing up in its migratory path, a situation which did not bode well for the future.

“Land up to the edge of the canyon is important for both foraging and accessing the canyon,” explains Miyasaki, adding that the more time deer spend reacting to humans, the less energy they have to make it through the winter. “This isn’t a herd that’s got it easy by any means—they have some of the most severe winter range in our area. They need all these components [functional migration corridors; winter and summer range] in their life history to make it.”
But since the real estate boom disintegrated into a bust, much of that land has gone back to the farmers. Lucia says that while potato fields aren’t ideal, at least agricultural land doesn’t inhibit migratory movements like subdivisions would have.

Currently, the Bureau of Land Management’s Upper Snake Field Office, which oversees 3,500 acres of public land in the Teton River Canyon, is revising its Resources Management Plan. By January 2013, the BLM hopes to release a draft for public comment regarding management plans for land it administers in the canyon. Several of the proposed options include designating the BLM’s 3,500 acres as an Area of Critical Environmental Concern (ACEC). Brought to the attention of the BLM in 2008 by several governmental agencies and the TRLT, the area is considered worthy of consideration for designation due to its scenic attributes, noteworthy wildlife and aquatic habitats, and riparian and upland communities.

ACEC designation could limit certain kinds of activity on the land, like mineral extraction, logging, and/or motorized recreation. BLM public affairs manager Sarah Wheeler emphasizes that the ACEC designation wouldn’t affect private land, but it could present funding opportunities for landowners interested in creating conservation easements on their property.

“We’re not looking to preemptively take over someone’s land,” Wheeler says. “The [ACEC] designation just allows for better funding opportunities—federal dollars become available to purchase conservation easements.” She points to the Henry’s Lake area, north of Teton Valley near the Montana border, and the South Fork of the Snake River, two places where this approach has been successful.

While some residents may lament the potential economic gains never realized due to now-defunct developments, a healthy deer population creates another moneymaking opportunity—one that’s yet to receive much attention in Teton Valley. According to Cavallaro, deer fawns in the Teton herd tend to be bigger than fawns in other parts of the state, due to the quality forage on their summer ranges. Many other herds must rely on the scant offerings of a desert landscape during the summer. A tag offering the opportunity to hunt a Teton buck in the fall is a prize. This past year just fifteen tags were issued.

“It’s a big asset—a large deer herd,” says Gary Robson of Robson Outfitters, who’s been guiding hunters in the area since 1968. Robson has clients fly in each year from around the country, hoping to bag a Teton buck. “From an outfitter’s perspective, there’s a lot of revenue that comes to the state from those tags.”

But it’s not only the state coffers that see economic benefit from hunting. According to the Idaho Legislative Sportsmen’s Caucus, statewide hunting supports 11,500 jobs and generates upwards of $598 million dollars each year through the purchase of equipment, hunting tags, outfitter fees, food, and lodging. Teton Valley hasn’t yet maximized the economic opportunity, and Robson doesn’t mind admitting that there’s room for more hunting guides here. “It could expand a lot,” he says.

While Robson sees large predators like wolves and cougars as threats, he also acknowledges that development could endanger the herd and, in turn, his livelihood. “Any time you’re digging up their habitat and building a house, that’s going to hurt their population a little,” he says.

To date, the Jackson Hole conservation community has demonstrated little interest in the Teton River Canyon mule deer herd, despite the fact that the animals spend part of their year in Teton County, Wyoming. Nonprofits and land managers alike are hopeful that Jackson conservationists will begin to take note.

“How can we get more engagement from nonprofit and conservation groups based in Jackson?” asks Lucia. “This part of Wyoming [on the Tetons’ west side] doesn’t get as much attention as the other side of the slope.”

While humans may make a distinction as they migrate from one side of the Tetons to the other, the animals have yet to see the difference. It’s all just home to them.