Safe Passage

The I-40 Pigeon River Gorge Wildlife Crossing Project

safe passage

Road ecologists study the intersection of transportation and the wild

By Jennifer Fullford, Smokies Life lead editor

This article originally appeared in Smokies LIVE, the blog of Smokies Life, a nonprofit partner of Great Smoky Mountains National Park and steering committee member of Safe Passage.

Roads and ecology seem to be at opposing ends of the environmental spectrum. How can roads be ecological? A growing group of scientists is studying how they affect ecosystems, and many advocates and wildlife specialists are hopping on the wagon.

Groups from ICOET toured animal crossing projects in Colorado. Often, crossings develop because of the involvement of government staff and officials and buy-in from states’ departments of transportation. Photo courtesy of UC Davis, Road Ecology Center.
Groups from ICOET toured animal crossing projects in Colorado. Often, crossings develop because of the involvement of government staff and officials and buy-in from states’ departments of transportation. Photo courtesy of UC Davis, Road Ecology Center.

The relatively nascent field of road ecology looks at the impact of transportation on ecosystems. All those roads, byways, and paved pathways—four million miles in the US—that build in convenience for humans also lead to less positive consequences for animals and land. An estimated one million animals are killed on US roads every day.

Across the country, including in the Smokies, a new road ecology ethos is producing experts who are studying how our byways change the landscape—be it habitat, connectivity for animals, or the health of wildlands. It’s predicted that commerce will continue to fuel future growth in transportation, which has new road ecologists even more keenly attuned to outcomes in the natural world.

“To us, roads signify connection and escape,” writes journalist and award-winning author Ben Goldfarb. “To other life forms, they spell death and division.”

Goldfarb gave the keynote address at the recent International Conference on Ecology and Transportation, held this May in Denver. ICOET attracts road ecologists and enthusiasts worldwide, from the desert of the US Southwest to locales in Africa, Latin America, and Norway. Goldfarb is considered the movement’s poster child, racking up awards for his recent book, Crossings: How Road Ecology is Shaping the Future of Our Planet (W. W. Norton 2024). He loosely defines road ecology as the study of how life changes for plants and animals when a road appears nearby.

A focal point for road ecologists is the biennial International Conference on Ecology and Transportation, held earlier this year in Denver. People from around the world, including Africa, the Netherlands, Latin America, and the US, are part of the road ecology community. Photo courtesy of UC Davis, Road Ecology Center.
A focal point for road ecologists is the biennial International Conference on Ecology and Transportation, held earlier this year in Denver. People from around the world, including Africa, the Netherlands, Latin America, and the US, are part of the road ecology community. Photo courtesy of UC Davis, Road Ecology Center.

“Writers have always been sensitive to issues around roads and the environment,” Goldfarb said in his ICOET opening address. As an example, he referenced Mary Oliver and her poem, The Black Snake, which starts with a universally accepted evil—roadkill.

When the black snake
flashed onto the morning road,
and the truck could not swerve–
death, that is how it happens.

But Goldfarb is not all doom and gloom. In fact, he gives talks that inspire a few smiles because of the dichotomy between the very human joy of wanderlust versus its environmental impact, which he emphasizes entangles more than just large animals.

“Remember the herps and turtles, reptiles and snakes!” he said to chuckles of recognition from the ICOET’s crowd, many of whom are scientists. Later, the ICOET schedule included a movie about tarantulas and a panel discussion focused solely on spiders, “Arach-No-phobia: Perspectives and Results From a Unique, Collaborative Study of Tarantulas in Southeast Colorado.” Other smaller animals also got their due throughout the conference week in May. Several presentations attracted large crowds about projects involving newts and bats, whose study has spun off its own genetic identification service at Northern Arizona University (Species From Feces).

Ben Goldfarb standing at a podium in a gray suit coat and blue button down shirt.
Ben Goldfarb, known for his highly acclaimed 2024 book “Crossings” about road ecology, gave the keynote address at the International Conference on Ecology and Transportation in Denver this May. Photo courtesy of UC Davis, Road Ecology Center.

Since 2003, ICOET has become a biennial point of reference and opportunity to learn and network for not only the people who study, govern, and advocate for better transportation, but also for those who are finding entrepreneurial ways to support systems less harmful to biodiversity.

An entrepreneurial spirit is rising with the use of technology and data analysis. Dozens of businesses, such as HDR Inc. in Coopers Landing, Alaska, and ERTECH manufacturing in Alameda, California, signed on this year as conference sponsors. Animex International presented its work producing fencing to decrease mortality rates of smaller animals that cross big roadways. Those businesses sit with a growing list of communities, states, and countries that are striving to, firstly, gather data and, eventually, create better infrastructure to reduce wildlife–vehicle collisions and support more ideal habitat.

Lest it’s understated, road ecologists do not deny the benefits of transportation networks: avocados from California, pizza deliveries to our door, easy access to faraway places. There’s little argument that transportation is an essential component of commerce, recreation, and basic human connection. And, when considered thoughtfully and holistically, it can improve the lives of human and animals. More strategic approaches to transportation are a key component of the greater road ecology movement.

How people are innovating is shaped by place and, oftentimes, passion. Take, for instance, Jessica Moreno, conservation science director of the Coalition for Sonoran Desert Protection, who says she sees people become inspired by simply seeing wildlife camera footage and photos of difficult crossings in the desert. The coalition is celebrating a successful collaboration to remove old barbed-wire fencing on private land. Since 2021, the effort has removed about 70 miles of redundant fencing.

An outcome of road ecology efforts in the Southwest is the Desert Fence Busters project to remove excess barbed wire across public and private land in the Sonoran Desert. So far, about 70 miles of redundant fencing has been removed. Photo courtesy of Desert Fence Busters.
An outcome of road ecology efforts in the Southwest is the Desert Fence Busters project to remove excess barbed wire across public and private land in the Sonoran Desert. So far, about 70 miles of redundant fencing has been removed. Photo courtesy of Desert Fence Busters.

“The Desert Fence Busters project is something that we started recently, and we have employees and volunteers from Arizona Game and Fish, hunting groups, nonprofits like ourselves and the Tucson Bird Alliance, previously known as the Tucson Audubon Society, students, Sonora National Park—the gambit,” she said. “It’s amazing. We’ll have 65-plus volunteers each trip.”

Removing harmful fencing seems like a no-brainer, yet it is evidence that the scope is widening for inexpensive, outside-the-box efforts that can make a difference.

Projects in Appalachia also earned podium-time. One by Liz Hillard of Asheville, North Carolina, for Wildlands Network took stock of road underpasses for crossings by timber rattlesnakes (Crotalus horridus) and other species of concern in Southern Appalachia. For rattlers, a female first becomes fertile around nine years old and generally won’t produce offspring each year, she said, so keeping the females alive to propagate the species is essential.

“We’re behind, but the work needs to start now if we want to save our species, as they need to move, and we want to help them do that,” Hillard said.

An interstate project in Colorado drew a tour group from ICOET to see a mountain corridor project—double-span bridges under six lanes designed to reduce collisions and provide a safe passageway for elk, mule deer, and other wildlife. Photo courtesy of UC Davis, Road Ecology Center.
An interstate project in Colorado drew a tour group from ICOET to see a mountain corridor project—double-span bridges under six lanes designed to reduce collisions and provide a safe passageway for elk, mule deer, and other wildlife. Photo courtesy of UC Davis, Road Ecology Center.

Her work has also helped Safe Passage, a coalition in Western North Carolina and East Tennessee supported by Smokies Life, that has been doing road ecology groundwork for more than seven years, a period that has seen a surge in advocacy.  She and Steve Goodman of the National Parks Conservation Association conducted field research over three years to evaluate how roadways outside Great Smoky Mountains National Park influence the connectivity of habitat for black bear, white-tailed deer, and elk. Their work resulted in more than a hundred specific recommendations for departments of transportation to improve wildlife permeability in the Pigeon River Gorge, some of which are now being implemented.

For many professionals in road ecology, more sophisticated and safer transportation and land-planning projects around the US and elsewhere are more than simply possible—they’re coming to fruition. And in the words of Thomas Lovejoy, famed American ecologist, “The choice is not between wild places and people, it is between a rich or impoverished existence . . .”

Recommended reading/viewing
Watch the ICOET 2025 presentations on YouTube. Read Rewilding Institute’s review of Goldfarb’s 2024 book on road ecology. Check out Smithsonian magazine’s excerpt from Goldfarb’s book.

I-40 rebuild offers rare opportunity for wildlife conservation

Please note: Since this story published in November 2024, North Carolina Governor Josh Stein announced that two lanes of Interstate 40 through the Pigeon River Gorge are expected to re-open March 1, 2025.

Featured in (from left) Asheville Citizen Times, Smoky Mountain Living magazine, Smoky Mountain News, and Knoxville News Sentinel.

By Holly Kays
When the Safe Passage coalition started working in 2017 to make Interstate 40 a safer place for people and wildlife through the Pigeon River Gorge, nobody knew that, in a few short years, entire sections of the critical roadway would vanish in the wake of Hurricane Helene. The scale of Helene’s damage was unfathomable, with 106 people confirmed dead in North Carolina alone and survivors left to contend with tens of billions of dollars in damages to property and infrastructure. The region is in mourning—but the rebuilding process may offer a once-in-a-generation opportunity to save the lives of future travelers.

“If we want to look for silver linings, I think there is a chance that we could use this long pause in traffic on I-40 to create some win-wins for wildlife, driver safety, and flood resilience along the road,” said Ron Sutherland, chief scientist for coalition partner Wildlands Network.

The 28-mile stretch of I-40 that passes through the Pigeon River Gorge bisects a rugged landscape that falls mostly within the Pisgah National Forest, Cherokee National Forest, and Great Smoky Mountains National Park. It’s one of the most biodiverse places on the planet, and before Helene, the road handled about 26,500 vehicles every day—a formidable barrier to natural wildlife movement across the landscape. Between 2018 and 2020, researchers Liz Hillard of Wildlands Network and Steve Goodman of National Parks Conservation Association analyzed 304 collisions between vehicles and large animals like bear, deer, and elk. Nationwide, wildlife–vehicle collisions kill more than 200 people annually and cost over $10 billion, according to a 2023 report from the Federal Highway Administration.

Through collaboration with government agencies and efforts to secure funding for wildlife crossings, Safe Passage has been working toward infrastructure solutions that would prevent such crashes from happening. Thanks to the group’s partnership with the NC Department of Transportation, the designs for five I-40 bridges up for replacement were amended to include wildlife-friendly modifications, and the agency was poised to use a $2 million wildlife-crossing allotment from the NC General Assembly to install fencing and evaluate Wildlands Network’s and NPCA’s research-based proposals for improving connectivity in the gorge.

Then Helene struck.

The hurricane hit the Gulf Coast as a Category 4 storm and then moved north, dropping record-setting amounts of rain on communities across Southern Appalachia. A gauge on the Pigeon River just below the power plant at Waterville, located along the I-40 corridor, jumped from its normal level of four feet up to nearly 22 feet before the river tore the gauge out around 10 a.m. September 27, as the worst of the flooding unfolded. Three of the five bridge replacements were completed, or nearly so, when the hurricane arrived, and they came through mostly unscathed. However, other areas of the road incurred catastrophic damage. Eastbound lanes in the four-mile stretch between the Tennessee–North Carolina state line and North Carolina mile marker 4, where both east- and westbound lanes of traffic disappear into a tunnel, bore the brunt of the destruction. In some places, the shoulder is gone. In others, one lane crumbled, and in some, both lanes are missing. The road saw significant damage on the Tennessee side of the state line too, with the eastbound lanes damaged in multiple locations from mile 446 to the state line at mile 451.

“Because of the alignment of the river versus the road coming in from an angle, the water got in behind walls,” explained Wanda Payne, Division 14 engineer for NCDOT. “And so once it got behind those walls, it just ate out the dirt. It’s like ‘between a rock and a hard place,’ except our hard place wasn’t as hard as we thought it was, so the rock won.”

In the most-affected areas of I-40, entire lanes of highway were carried away, as was the soil on which they once rested. Photo provided by NCDOT.

The highway between Maggie Valley and the state line has been closed since the storm as NCDOT develops plans for both emergency stabilization and long-term repair, while the adjoining five miles in Tennessee are open only as a two-lane road for local, noncommercial traffic. As of February 10, there were still 172 road closures in effect across North Carolina, with roughly 8,000 sites damaged, including at least 140 bridges in need of replacement. NCDOT continues to chip away at this massive to do list.

“I definitely sympathize with the DOT, because they’re in a position where they feel like they need to be racing ahead to get all these things put back in place, but at the same time, I hope that the public can see the opportunity here,” said Sutherland. “We can make it so that the next time a big storm like Helene comes through, our infrastructure actually survives.”

For this, Sutherland sees Vermont as a role model. Hurricane Irene inflicted massive damage on the state in 2011, and afterward Vermont invested nearly $230 million in 130 infrastructure projects designed to withstand similar weather events in the future. The state saw another round of major flooding in 2023, and those sites were either undamaged or minimally impacted.

Any bridge or culvert that can survive a storm like Helene will need to be “absurdly big and strong,” Sutherland said, ensuring space to install culverts or underpasses large enough for bear, deer, and other animals. Wildlands Network recently completed an analysis of North Carolina bridges damaged by Helene that prioritizes their importance for wildlife connectivity.

Two bobcats climb into a culvert that runs under I-40. They will use the pipe to reach the other side of the highway without crossing traffic. Photo provided by National Parks Conservation Association, Wildlands Network.

“If we’re able to put in better bridges that are more floodproof and stronger and bigger on even a quarter or half of those sites,” Sutherland said, “that’s going to have huge benefits for wildlife.”

But it’s a time-sensitive issue. The DOT is working to restore the state’s transportation infrastructure as quickly as possible, an undertaking expected to be extremely expensive, even without considering wildlife crossings. The Safe Passage group is working hard to offer planners its input and help secure funding for installations that could benefit wildlife for generations to come.

“If we miss this opportunity, then Hurricane Helene could have the counterintuitive result of foreclosing on the likelihood for wildlife improvements at hundreds of sites over the next 50 years,” Sutherland said. “Who will want to tear out shiny new bridges and culverts?”

NCDOT structures destroyed by Helene had an average age of 60, meaning that many of them would have been up for replacement in the coming years. Losing the opportunity to improve their utility for wildlife post-Helene would be a “serious setback,” Sutherland said.

The Pigeon River Gorge continues to be a top priority for Safe Passage. The area damaged by Helene includes four sites in Tennessee and three in North Carolina that the research from Wildlands Network and NPCA flagged for wildlife-crossing concerns. In any highway project, rerouting traffic comprises a significant percentage of the budget—but if wildlife-crossing structures could be dropped in while the road is still closed, these improvements could be made with less hassle or expense than will likely be possible again anytime soon.

Safe Passage’s earlier efforts to coordinate with transportation planners have paved the way to make such an outcome more likely than it would have been prior to the group’s formation—Payne said that NCDOT’s plans will address wildlife concerns mentioned in the report. But what that repair might look like is still an open question. In many places, the entire bedrock on which the road rested is gone. NCDOT may decide against rebuilding I-40 exactly as it was before.

Due to potential difficulty in securing reimbursement from the Federal Highway Administration, it’s unlikely NDOT will choose to reroute the entire corridor. However, realignment within the most-affected area is a possibility, as are walls, viaducts, and bridges. The NCDOT awarded Wright Brothers Construction an $8.5 million contract to perform temporary emergency repairs on the road and had expected to open the westbound lanes for two-way traffic by New Year’s Day. However, that timeline was delayed when a large chunk of concrete fell from one of the eastbound lanes, NCDOT announced December 20. The road is now expected to accommodate two-way traffic starting March 1, with a speed limit of 40 miles per hour.   Tennessee is working to reopen all lanes of I-40 in its jurisdiction by the end of the year, and NCDOT expects to do so by October 2026. It has hired Ames Construction as contractor, RK&K as designer, and HNTB as project manager. Payne wants all three parties to meet with Safe Passage early in the process to discuss how wildlife crossings should factor into the design.

Rebuild stronger infrastructure now so NC can save later, featured in Raleigh News & Observer

By Ron Southerland

The Pigeon River damaged or destroyed the eastbound lanes of Interstate 40 in several places after the remnants of Hurricane Helene dropped historic amounts of rain on Western North Carolina. This photo was taken about four miles from the Tennessee line. Photo courtesy of NCDOT.

When Vermont was hit by Hurricane Irene in 2011, its infrastructure was shattered, just as ours in North Carolina is now. Someone up there had the wisdom to make sure every culvert, bridge and building that was destroyed was replaced by a version that was bigger, stronger and more resilient to flooding. I suggest North Carolina take the same approach, with substantial support from the federal government and our own General Assembly. It may be expensive up front but provides significant savings and much faster recovery from storms down the road.

Read the full Raleigh News & Observer feature here.

Creating Safe Passage, featured in Blue Ridge Outdoors

By Holly Kays

Photo by Michele Sons.

Extensive efforts to add highway wildlife crossings near the Smokies aim to protect animals and people

Editor’s Note: This story was published in the October issue of Blue Ridge Outdoors before Hurricane Helene devastated portions of western North Carolina and surrounding areas. Due to extensive flood damage on Interstates 40 and 26, the Safe Passage Fund Coalition is adapting its ongoing work to include assessing the affects of the storm to recently installed crossing improvements and working to collaborate with environmental and government partners to prioritize animal and human safety as these highways are being repaired and rebuilt.

By 10 p.m., interstate 40 was dark and deserted as North Carolina State Representative Sarah Crawford and her husband Dan cruised east past Morganton, N.C. They were eager to reach their hotel for some rest between the wedding they’d just attended and the comedy show and baseball game planned for the next day. 

Then the car stopped “like we had hit a brick wall,” said Sarah Crawford, a Wake County representative in the North Carolina General Assembly. 

In fact, they’d hit a 200-pound bear. Every air bag deployed, the front fender crumpled, and the car was left motionless in the dark—on a road where most people drive 70 miles per hour or more. Though the couple managed to escape mostly unscathed, the car was totaled, and the bear was dead.

It was a “pretty scary incident” that sent Crawford “down a rabbit hole” searching for information about how to make roads safer for both human travelers and native wildlife. That journey led her directly to the Safe Passage coalition, a group of people and organizations that has been working since 2017 to make wildlife crossings safer not only in its focus area of the Pigeon River Gorge, but also in hotspots across North Carolina and Tennessee. 

“We at Safe Passage often use the tagline, ‘what’s good for wildlife is good for people,’” said Tim Gestwicki, the coalition’s steering committee chair and CEO of the North Carolina Wildlife Federation. “And clearly, if they run into a large animal, the danger is there for people too. So it’s a perfect nexus of people and wildlife safety.”

Photo courtesy of NPCA/Wildlands Network.

Over the years, Safe Passage has become an increasingly organized collaborative of dedicated partners involved in everything from transportation planning to educational outreach and lobbying efforts—work that is predicated on foundational research it conducted starting in 2018. Coalition partners Wildlands Network and National Parks Conservation Association hired researchers Liz Hillard and Steve Goodman to tackle the project, and the pair placed 120 cameras along the 28-mile Pigeon River Gorge corridor. This stretch of Interstate 40 straddles the North Carolina-Tennessee line, bisecting a rugged landscape that falls mostly within either the Pisgah National Forest, Cherokee National Forest, or Great Smoky Mountains National Park. 

View the full Blue Ridge Outdoors feature here.

NC Residents: Urgent action is needed for wildlife!

The North Carolina General Assembly opens this week, and the Safe Passage Coalition is asking legislators to set aside funds for wildlife crossings across the state. 

We need your help!

North Carolina residents, please contact your representatives today and urge them to support $10 million for targeted funding for wildlife crossings in the state budget this year. A sample below can aid in messaging. 

If you don’t know who your N.C. representatives are or how to reach them, please visit ncleg.gov/findyourlegislators.

Read on for more details on this effort. 

Thank you for speaking up for wildlife! 

— Your friends at Safe Passage Coalition 

FIND YOUR REPRESENTATIVE

Dear Representative/Senator ______,

I am a constituent of yours from [CITY], North Carolina, and I am urging you to support $10 million in targeted state funding for wildlife crossings. Wildlife and motorists across our state need added protections on roadways; according to State Farm, North Carolina is a high-risk state for animal-vehicle collisions, coming in at 16th in the nation. Estimates show that these collisions cost N.C. a total of $400-$500 million per year.

Wildlife crossings can take various forms based on location, from simple fencing around underpasses and culverts to overpasses spanning the roadway. Properly designed wildlife crossings pay for themselves in costs saved for emergency and medical assistance, property damage, and value of animals lost.

Please support targeted state funding to improve motorist safety, reduce collision costs, and protect valued natural resources.

Thank you, 

[YOUR NAME]

COPY SAMPLE TEXT TO AN EMAIL*

*When using the email template from this link, remember to add in your representative’s email address and name, as well as your own town or city. 
Click here to find your legislator’s contact information.

Why support funding for wildlife crossings in North Carolina?

NC Fact Sheet 2024Download

Wildlife Conservation Spotlight: UT researcher Kristin Botzet contributes valuable data to bear movements in Pigeon River Gorge

By Kimberly Smith
EBCI Citizen, Southern Appalachian Representative for The Wilderness Society and Safe Passage Outreach Committee member

In March, we celebrated Women’s Herstory Month and recognized the invaluable contributions of women in the field of science and conservation. As a member of the Safe Passage Outreach Committee and a graduate of the University of Tennessee Knoxville (UTK), I am excited to shine the spotlight on a remarkable woman, Kristin Botzet, a UTK MS candidate, whose groundbreaking research is shaping the future of wildlife conservation in the Safe Passage I-40 Pigeon River Gorge project area and throughout the Southern Appalachian Mountains.

As we know, the Pigeon River Gorge is a critical corridor for wildlife and human movement. Here, Kristin and her team researched bear movement patterns. “While conducting my graduate research assessing the movements and outcomes of relocated black bears, I observed a remarkable occurrence,” she said. “One of the bears managed to navigate across I-40 an astounding seven times in a single month. Anyone familiar with the area, and that route knows what a feat that is; many bears don’t share that kind of luck.” Their findings are not only shedding light on the behavior of these iconic creatures but also informing conservation efforts to protect their habitat.

Beyond research, Kristin is passionate about engaging local communities and raising awareness about wildlife conservation. She gives presentations on bear biology and wildlife career opportunities to school groups at the Tremont Institute in the Great Smoky Mountains National Park. Through outreach activities and educational programs, she aims to inspire a new generation of conservationists. Safe Passage’s collaboration with grassroots organizations and Indigenous communities further amplifies their impact, fostering a deeper connection between people and nature. By being stewards of the land, we become the voices for those without words, the advocates for ancient trails, animals, plants and waters. Safe passage isn’t just about roads for two-legged; it’s about access for all, ensuring all creatures on this land and in these waters can journey unimpeded, that their habitats are intact, and their futures intertwine with ours.

Adult bears that become accustomed to foraging for human food or garbage may grow bold or persistent, prompting park rangers to capture and relocate them outside the park, hoping to help mitigate any potential human–bear conflicts. 

But what happens to bears after they are relocated? 

Recently, a research team from the University of Tennessee in Knoxville (including graduate student lead researcher Kristin Botzet) set out to answer that very question — and they found that these bears often die within a few months of being moved. Many are struck by vehicles while attempting to cross roadways, including I-40, as they try to make their way back to the park.

University of Tennessee researcher and graduate student Kristin Botzet with an immobilized 393-pound male black bear, known as UT11 in the study.

Kristin’s journey into wildlife research is a testament to the power of passion and perseverance. Inspired by her childhood love for the outdoors, she embarked on a quest to explore her curiosity of animal movement patterns. “I have always been intrigued by the natural world, but in ways beyond thinking animals were cute and cuddly,” she said. “My childhood was devoured by endless hours playing ‘Zoo Tycoon’ and studying my grandpa’s animal encyclopedia. I even repeatedly rented the same ‘Really Wild Animals’ VHS tapes.” From her early days exploring nature to her current role as a M.S. candidate, Kristin has overcome challenges and blazed a trail for women in science. “Today, my 8-year-old self would be very proud. She answered the famous ‘What do you want to be when you grow up’ question in my third grade yearbook with ‘wildlife biologist,’ and here I am.”

As Kristin continues her research journey, her vision for the future is clear: to bridge the gap between science and advocacy. “I hope that my work inspires not only women but anyone who has a spark of interest in the field of natural resources and ecology,” she said. “The field of wildlife research is small, but critical, especially today. We need more people willing to contribute to meaningful change, and frankly, it’s a career path often overlooked because it really isn’t talked about in our primary education system.” With Safe Passage’s support, she hopes to translate her findings into actionable solutions, advocating for wildlife conservation at the local, state, and national levels. Together, we are building a more sustainable future for wildlife and humanity alike.