The Key to Solving Big-Game Migration Conflicts? Roadkill

NICK SCHRIVER LOOKS at highways the way a contractor looks at your house. He sees trouble spots that can use some touch-ups, if not total reconstructions. The maintenance supervisor for the Montana Department of Transportation’s northeast field office, Schriver is tasked with making sure roads in his district are intact and as safe as intended.

His is no office job. Instead, Schriver drives a thousand miles of two-lane in his MDT pickup at least once a week, noting damaged signs, crumbling asphalt, plugged culverts, and roadkill. Always roadkill. His district includes some of the gamiest landscapes in North America, swaths of open prairie that pronghorn antelope cross on their thousand-year-old seasonal migrations, riverbottoms full of whitetails, and Hi-Line two-lanes dotted with grazing mule deer.

Schriver takes me on a tour of the most problematic areas in his district, spots where roadside vegetation grows right up to the shoulder, obscuring wildlife. Or stretches where the terrain funnels migrating antelope into just a few hundred yards of blacktop.

“Here’s one where I bet we’ve picked up dozens, maybe even hundreds, of dead deer over the years,” says Schriver, stopping on the narrow shoulder on the east side of Nashua, a little town on U.S. Highway 2 between the prairie oases of Glasgow and Wolf Point. “Mix of whitetails and muleys, and the occasional antelope in bad winters when the snow pushes them onto the highway. The only reason more deer aren’t killed here is because the speed limit is still 55” coming out of the city limits.

On one side of the highway, Porcupine Creek meanders through groves of shady ash trees. On the other side stands a winter wheat field. It’s a classic transition zone between cover and feed, and Schriver says that for motorists who aren’t watchful, it’s a chronic trouble spot for collisions as deer move between the habitats. I see glints of safety glass and shards of reflector and turn-signal plastic all along the shoulder. Just ahead is a white cross on a metal T-post, signifying the very spot where a driver died.

picking up elk carcass on highway
Clearing ungulates struck by vehicles, like this Wyoming elk, is a full-time job for Western transportation workers. Ryan Dorgan/Jackson Hole News & Guide/AP

Wildlife collisions are routinely reported to the Montana Highway Patrol, either by an officer who responds to the scene or by a motorist recording the incident for insurance purposes. But many more accidents are never documented, says Tom Martin, environmental bureau chief in the Montana Department of Transportation’s Helena headquarters.

“If a trucker hits a deer, that usually doesn’t cause them to stop,” says Martin. “So there was a collision, but it was never reported, but later we find a carcass. We know that carcass data is usually higher than collision data. And our carcass data is conservative.”

By “conservative,” Martin means that roadkill totals are certainly higher than reported. The actual carnage, all gristle and paunch, is collected by Schriver’s teams. These are the carrion crews, MDT workers who patrol their districts at least weekly, peeling up the carcasses of shattered deer and putrid porcupines. Not every carcass makes it onto the flatbed of the pickup and then to a landfill. In remote areas, the crew sometimes drags remains far off the highway, leaving them where scavengers won’t be likely to become roadkill themselves. But no matter what they do with the carcass, every time crews encounter roadkill, they note the location, species, and condition. That information is also sent to Helena, where it joins the collision reports in the most grisly database in Montana, maintained by MDT’s Doug McBroom.

“We have about 30,000 data points that we’ve entered since we went live with our digital reporting system in 2017,” says McBroom, who shares his collision location data with the folks who design and build Montana’s highways. These statistics are a tributary for a river of information increasingly being used to reduce roadkill and to ensure that wildlife can remain the punchline of the easiest of jokes: to get to the other side.

A Hazardous Reality

Every deer crash is a variation on Leo Tolstoy’s descriptions of human families: similar to others in its themes, but unhappy in its own special way.

Among the unfortunate shared details are too-late awareness of a twitchy deer on the shoulder, screeching tires, a black cloud of profanity, and the devastating crunch and shudder of impact. Then silence, hissing engine liquids, and hushed check-ins. “Are you OK?” “What just happened?” “Jesus…”

Intensity and damage parallels Bergmann’s Rule, the principle that larger species are found in northerly latitudes. Colliding with an elk or a moose is proportionately more catastrophic than hitting a raccoon or a squirrel. But no wildlife collision is happy, for either the motorist or the animal. Hitting wildlife with our cars costs Americans more than $8 billion annually, and the roadside carnage is astonishing. Every year we whack, smack, smoke, grease, and paste an estimated 2 million deer, pronghorns, rabbits, and bears with our cars. While some limp away, most animals die either on impact or shortly after from broken bones or internal hemorrhaging. Even graver are the human costs: 26,000 injuries and some 200 deaths every year.

highway warning sign
Busy roads and highways intersect with historic migration corridors all across the West. Michael Beiriger/Alamy

There are consequences for survivors. Motorists can be so traumatized by wildlife collisions that they avoid troublesome stretches of road, or stop driving altogether. For animals whose habitat is crossed by roads, avoiding death by bumper and grille is only part of the consideration. At a certain traffic intensity, wildlife simply stop trying to cross, vacating critical habitats; others must make problematic detours in order to cross safely.

But there is a surprising upside to all that carnage. Every deer, antelope, elk, or bear that is hit on a highway helps its survivors avoid the same fate. This is the story of the bright side of roadkill.

Post and Wire

After we leave the carnage of east Nashua, Nick Schriver takes me to a spot that has kept his carcass-collection crew busy for the past 30 years. It’s a stretch of Montana Highway 200 between the dusty town of Jordan and the hopefully-named crossroads of Flowing Wells, where the only water for miles around is dispensed by the toilets and washbasins of an official state highway rest stop.

As we drive west onto SR200 from Flowing Wells, Schriver prepares me for what we’re about to see.

“This was a spot where so many mule deer were hit that the locals got tired of slowing down for the live ones or stopping to drag the dead ones off the road.”

I’ve driven this stretch hundreds of times and always recognized it as problematic. It’s a place where adobe buttes slump right against the narrow roadway, and where meandering prairie streams come to a hard stop against the highway embankment. Every acre in every direction is deer habitat, and the two-lane itself seems out of place, a black line thrown across the rippled prairie. But Schriver shows me a new dimension to the highway, a wildlife-excluding fence under construction along the highway for maybe 30 miles west of Flowing Wells.

whitetail roadkill
Although mule deer are one of the big-game species most commonly struck on Western roads, whitetails are also frequent casualties. Donald M. Jones

In a landscape defined by endless horizons, the 10-foot-high fence seems even taller. This double-high woven-wire fence runs closer to the road than the standard 5-foot barbed cattle enclosure, and every mile or so is a curious gap that looks like a loading dock for 18-wheelers. These are “off-ramps” for deer and pronghorn antelope that might find their way inside the fence and be desperate to get out, Schriver tells me.

“The fence is designed to keep critters off the road, but sometimes they’ll get in an open end, and unless you have some way to get them out, it’s pretty much a death trap,” says Schriver. “I’d call those one-way ramps. They’re designed so that an animal can jump off to get off the highway, but an animal from outside is not going to be able to jump up on one to get onto the road.”

Schriver might not have built this fence, but his work contributed to its erection. All the data that he and his crew sent to McBroom over the years helped highlight this as one of a dozen “trouble spots” in the state that scare the shit out of every rural driver. These are the stretches of highway with limited visibility and such a constant presence of deer crossing the highway—or nervously about to—that you can tell visitors from locals because the latter drive slowly through these gauntlets.

wildlife bridges over highway
Funding for more wildlife crossings, like this one in the Canadian Rockies, promises to improve the worst trouble spots along North America’s roadways. Andrew McKean

The fence is called a “wildlife accommodation,” and you can expect to see a lot more of them in the coming years, in Montana and across the West. They’re culverts, underpasses, wildlife-friendly overcrossings, or any other infrastructure that lets wildlife pass over or under the road without getting smoked by a Suburban.

“An accommodation could be a safety need, for humans and for animals, or it could be a connectivity need—animals are having trouble getting from one side of the road to the other, for whatever reason,” says the MDT’s Tom Martin. “But safety is really the biggest one for us.”

Tunnels and Bridges

Those accommodations often start with a simple sign. All those yellow signs featuring a leaping deer or elk or the words “Wildlife Crossing” that we routinely ignore were erected for a reason: Those are spots where drivers just like you regularly hit animals.

Next is exclusionary fencing, like what’s on Highway 200, or the replacement of barbed wire with smooth wire as the lowest strand of a standard roadside fence. The smooth wire allows antelope to scoot under the fence and cross the road quickly rather than milling along the shoulder, impeded by the barbed wire.

In the Southwest, where endangered desert tortoises are particularly susceptible to being hit by vehicles as they move (slowly) between seasonal habitats, the fence mesh is finer—1×2-inch squares—and the fence itself is lower—only 24 inches high. But the tortoise fence does the same thing as a deer fence—it funnels animals to specially designed culverts where they can safely cross underneath the highway.

Because they’re cheapest, fences are often the first option considered, followed by culverts. The most expensive options—sometimes costing tens of millions of dollars—are over-crossings, or wildlife-friendly bridges. The costs of building and maintenance are always taken into account before they’re added to a highway project, says Martin. That’s because while the federal government funds cover three-quarters of most state highway construction and reconstruction projects, ongoing maintenance is covered entirely by state funds.

“We want to make sure [every accommodation is] reasonable and feasible and that we have the budget to take care of it long-term,” he says. That means 30 years for highway surfaces and 100 years for bridge structures. “If it meets all those criteria, then it gets put into plans and contractors build it.”

dead mule deer caught in fence
A mule deer didn’t survive its attempt to navigate this fence. While roads are major migration barriers in the West, fencing is also a problem. Joe Riis/Yellowstone Migrations

Roadkill by the Numbers

With 8,100 miles of roads maintained by the Department of Transportation alone and abundant big-game herds in every corner of the state, Montana has lots of opportunity for wildlife collisions. Second only to West Virginia in State Farm Insurance’s national animal-collision probability rankings, Montana is nonetheless well behind its neighbor Wyoming in addressing roadkill.

The Wyoming Wildlife and Roadways Initiative aims to direct some $10 million in federal infrastructure funding to reducing the 6,000 annual wildlife collisions across the state. By far, the species most likely to die by vehicle in the Cowboy State is the mule deer. The Wyoming Game and Fish Department estimates that 4 percent of the state’s mule deer population is killed by cars every year. But that $10 million is just for determining where and what kinds of accommodations might reduce the carnage. The price of constructing them will be in the billions, paid mainly by the federal government.

That federal pot just got a lot bigger. As part of last December’s federal infrastructure law, Congress dedicated $350 million over five years to the Wildlife Crossings Pilot Program, which aims to incentivize states, municipalities, tribes, and NGOs to submit plans to reduce wildlife mortality in the spots with the biggest roadkill problems. That’s in addition to the $350 billion the law appropriated for highway projects over the next five years.

From offices in Bozeman, Montana, the Center for Large Landscape Conservation is advising applicants on how best to secure these wildlife-crossing grants. The nonprofit has developed a best-practices toolkit to give applicants a solid chance of scoring a federal grant.

While the $350 million won’t build out all the wildlife accommodations needed, Anna Wearn, the CLLC’s director of governmental affairs, is hopeful that it represents a commitment to making the nation’s roadways less deadly and intrusive for wildlife, including aquatic animals such as fish and amphibians.

“In addition to the $350 million, there are billions [of dollars] available for wildlife crossings and habitat connectivity projects sprinkled through about a dozen federal transportation programs,” says Wearn. “We’re optimistic that if folks follow the recommendations in our toolkit and design compelling and scientifically informed proposals, that they will be competitive for funding under those multibillion[-dollar] transportation programs.”

pronghorn with foot caught in fence
A pronghorn gets hung up in a cattle fence. Fencing in the West can obstruct migrating game, but it can also be used to safely funnel animals. Joe Riis / Yellowstone Migrations

Building roads that are safe for motorists and permeable for migrating wildlife is not only in the national interest, says Wearn, it’s also one of the few bipartisan issues in Congress and state legislatures right now. It’s also cost-effective.

“There are so few conservation issues where we have a technical solution that’s up to 98 percent effective in solving a problem,” says Wearn. “And these projects pay for themselves within a number of years, depending on the size, number, and species [of animal] getting hit. The more effective a project is, the faster the return on the investment.”

Reducing human injury and death from wildlife collisions is also a huge savings not only in anguish and hospitalization, but also in lifetime productivity. One of the grimmer achievements of the insurance industry is the creation of the Human Life Value Calculator, which can put a price tag on you. Designed to assess how much life insurance is required to fully insure your life against future earnings, the calculator is used to justify the cost of accident-reducing highway projects. Even a single life saved can offset millions of dollars in construction costs.

Some of these infrastructure projects are staggering in both price and ambition. Construction on the largest wildlife-crossing initiative in history started this summer on U.S. Highway 101 in California’s Liberty Canyon. The $88 million Wallis Annenberg Wildlife Crossing is a vegetated bridge that connects the Santa Monica Mountains and the Sierra Madre Mountains and restores passage for mountain lions, mule deer, and wild canines that was cut off when the 10-lane Ventura Freeway was built in 1971.

Not all wildlife crossings have their own names and specific projects. In Florida, the state legislature approved the Florida Wildlife Corridor Act, which is using incentives to conserve up to 18 million acres of land from the Georgia border to the Everglades. The ambitious project aims to connect 10 million acres already under some sort of conservation protection in order to facilitate movement of endangered Florida panthers, native snakes and reptiles, even fish and aquatic plants.

Pronghorn migrating south near the town of Pinedale, WY. These pronghorn must migrate to southern Wyoming in order to find enough food and habitat for the witner. Joe Riis / Yellowstone Migrations

In New England, states are mapping and assessing their thousands of highway culverts to determine if they are impeding the passage of fish, amphibians, and reptiles. In Utah, a mobile app allows motorists to report roadkill, and just this year Wyoming rolled out a mobile app that allows drivers to claim roadkill for food.

Why all this energy, innovation, and attention on roadkill? Haven’t we been mowing down deer for as long as we’ve been driving cars? Liz Fairbank, a road ecologist with the CLLC, says several factors are converging to raise awareness of—and resolve conflicts between—highways and wildlife.

“First, we’re seeing increasing fragmentation and development of habitats,” she says. “Traffic volume is increasing and the number of lanes of traffic is increasing, and we’re seeing more impediments to wildlife movement in terms of roads and other types of development.”

But she says that we are getting better at quantifying the problem. The proliferation of GPS-enabled collars on wildlife has given us new insights into where wild animals move and how highways impede their passage. State highway statisticians, like Montana’s Doug McBroom, are also reporting roadkill and wildlife collisions more consistently, giving planners and engineers a better sense of historic trouble spots.

“Projects like the Wyoming Migration Initiative have shown the public how wildlife are making these long-distance movements and how they’re having to navigate a whole matrix of public and private lands and then fences, railroads, highways,” says Fairbank. “The issues of habitat fragmentation and migration impediments are finally coming into the mainstream. People weren’t aware of this even five years ago.”

Fairbank said another outcome of the confluence of road design and wildlife science is a reconsideration of whether more roads are necessary at all.

“A lot more projects are starting to be viewed through what we call the mitigation hierarchy,” says Fairbank. “The first step is avoidance. Do we really need this road in the first place? The second step is avoidance. OK, so we need this road, but let’s work to minimize its impacts. The third step is mitigation. We already have the road, and it’s going through sensitive habitat. That’s what we’re talking about when we talk about these wildlife accommodations: We’re mitigating the impacts of a road that we’ve concluded we need.”

Back in northeast Montana, Nick Shriver says his heart sinks a little every time he sees an antelope or a mule deer dead on the highway. His first thought is for the motorist, hoping they weren’t injured and that damage to their car wasn’t extensive. But then he thinks about the animal.

“They were just minding their business. It’s not their fault the road is there,” he says. Schriver pauses. “Besides, every deer dead on the road is one more deer I don’t get to hunt.”

This story originally ran in the Migrations Issue of Outdoor Life. Read more OL+ stories.

Andrew McKean Avatar

Andrew McKean

Hunting and Conservation Editor

Andrew McKean is Outdoor Life’s hunting and conservation editor, drilling into issues that affect wildlife, wildlands, and the people who care about them. He’s also OL’s optics editor, helping readers to make informed buying decisions.