Safe Passage

The I-40 Pigeon River Gorge Wildlife Crossing Project

pigeon river gorge

Why focus on the Pigeon River Gorge?

Aerial photos of I-40 in the Pigeon River Gorge by SouthWings.

By Steve Goodman, Safe Passage Co-Research Lead and Conservation Biologist for National Parks Conservation Association

Safe Passage is on a mission to improve wildlife’s ability to safely cross I-40 in the Pigeon River Gorge, resulting in improved public safety.

But, from a large landscape perspective, why have we chosen to expend valuable conservation and transportation resources here? And why now?

First, looking at a map of protected lands across the U.S., there is much less protected land in the East, and Great Smoky Mountains National Park and the surrounding national forest lands make up a substantial portion of it (Figure 1).

Furthermore, we’re right in the heart of The Nature Conservancy’s resilient and connected network designed to sustain biodiversity under a changing climate (Figure 2). This habitat corridor is critical for the long-term flow of regional plants and animals, yet I-40 has become a major barrier to wildlife movement. Researchers have estimated that in the Eastern U.S., only 2% of natural land areas retain enough connectivity to adequately allow plants and animals to track climate change. By adding wildlife corridors, we have an opportunity to increase that percentage tenfold.

Most compelling in a visual sense, however, is the now-famous Migrations in Motion map (Figure 3), produced by The Nature Conservancy. Based on modeling of the climactic needs of individual species, this animated map illustrates predicted movement routes of around 3,000 mammal, bird and amphibian taxa under current climate change projections, many of which are expected to track through the spine of the Southern Appalachians, including the Pigeon River Gorge.

Figure 1 – (Click to enlarge)
Figure 2 – (Click to enlarge)
Figure 3 – (Click to visit animated map)

Habituation at Harmon Den: Next steps for wildlife after crossing construction

After crossings are constructed, how soon can you expect wildlife to adapt to use new, safer passages?

Though infrastructure has been installed at the Harmon Den bridge in North Carolina (pictured above), more still must be done to attract wildlife to use the safer crossing. 

Progress is being made at the Harmon Den bridge in North Carolina, where our partners at the N.C. Department of Transportation recently constructed infrastructure for wildlife. Since then, we’ve begun some early monitoring of how wildlife are interacting with the new crossings, which include wildlife-friendly benches and cattle guards and will, in the future, include fencing.

Of course, it may take some time for wildlife to habituate to this improved crossing opportunity in the landscape, especially while vegetation in the area is still recovering from the recent construction. To improve success, it’s important that creekside vegetation — like fast-growing tulip popular, black birch, and red maple — continues to reestablish, as it will provide important cover and protection for traveling wildlife. Consideration should also be given, however, to restricting tractor trailer parking along the on- and off-ramps, which — because engines are often left running — creates noise and garbage (including human waste) that may potentially deter wildlife movement toward the new crossings. Another opportunity to encourage wildlife to use the crossings would be to clean up the crushed concrete spill that occurred during bridge construction along the bank of Cold Springs Creek.

Finally, it is important to note that although the opportunistic wildlife improvements at Harmon Den are important for wildlife connectivity and reducing vehicle collisions long-term, there are limitations to combined human–wildlife structures when compared to standalone structures for wildlife only. The Safe Passage Fund Coalition has made several research-based recommendations for standalone wildlife structures north and south of Harmon Den.

— Steve Goodman, Safe Passage Co-Research Lead

Day versus night view from the wildlife crossing at Harmon Den. Trucks parking on the on- and off-ramps can discourage wildlife from making the safe trip under the highway.

Spring signals a time for elk movement in the mountains

Elk 30216 and her calves throughout the years. During Safe Passage’s road ecology research in the Pigeon River Gorge, GPS collars revealed multiple years of one mother elk’s journey to and from her calving area.

While the elk population in and around Great Smoky Mountains National Park does not migrate, they do make some relatively longer seasonal movements. In these spring months, pregnant females will move away from their herd to give birth in isolated areas. Cows usually carry one calf and give birth in late May through June. In late summer when the calf is large enough, the pair will rejoin their herd, just in time for the rut (mating season) that occurs in late September through early October.

During our road ecology research in the Pigeon River Gorge, elk monitoring with GPS collars revealed multiple years of one elk’s journey to access her calving area. In both years of monitoring, she left the Cataloochee Valley in early spring and crossed the interstate to access her calving area north of the roadway.

In late summer, the cow and her calf would begin their journey back to the park, again having to navigate crossing I-40. In the two years of monitoring, this elk crossed I-40 107 times, with the majority of those crossings occurring at the Tennessee–North Carolina state border, where the Appalachian Trail crosses under the interstate via a road bridge, and also across a road surface just north of that area. 

In the map to the right, you can see her many crossings throughout the years — which she made both with and without her calves in tow, depending on the time of year. Each dot on the map represents the hourly location of this particular elk, Elk 30216.

— Liz Hillard, Safe Passage Co-Research Lead

Safe Passage research revealed the annual journey of one female elk, including 107 trips across I-40. Click the image to enlarge.

Research results unveiled for Safe Passage project area, providing framework for wildlife–vehicle collision prevention

The burden imposed by I-40 on wildlife habitat connectivity and transportation safety makes the Pigeon River Gorge a national priority site for wildlife–vehicle collision mitigation.

On June 29, two partners of the Safe Passage Fund Coalition — Wildlands Network and the National Parks Conservation Association — released their official report, Road Ecology Research and Mitigation Strategies to Improve Wildlife Connectivity and Human Safety along I-40 in the Pigeon River Gorge.

The much-anticipated report details the findings of more than three years of roadside research in the I-40 Pigeon River Gorge project area combined with analysis of 20 years of historical data. The study was one of largest road ecology research projects ever completed in the eastern United States.

The report was authored by a team of cooperating researchers and scientists:

  • Liz Hillard – Ph.D., Senior Wildlife Biologist, Wildlands Network
  • Steve Goodman – Conservation Biologist, National Parks Conservation Association
  • Ron Sutherland – Ph.D., Chief Scientist, Wildlands Network
  • Jeff Hunter – Southeast Regional Program Manager, National Parks Conservation Association

Based on the research findings, the report provides 20 detailed mitigation recommendations for improvements to existing structures or creation of new structures throughout the Gorge, and calls for installation of a system of strategically placed wildlife fencing. Additionally, through consensus, the report’s authors provide seven “top priority” recommendations, including key opportunities to construct wildlife overpasses and install larger culverts under the highway.

Click here to read the executive summary of the report, and click here to read the report in full.

READ THE SUMMARY

The research provides the framework for mitigation strategies to both improve existing structures and construct new wildlife-specific structures to reduce wildlife–vehicle collisions (WVCs) and increase wildlife habitat connectivity.

Fletcher students, Safe Passage partners met with N.C. Gov. Roy Cooper June 2 to advocate for wildlife crossings in the state

On June 2, North Carolina Governor Roy Cooper met with student supporters, representatives, and partners of the Safe Passage Fund Coalition in a roundtable discussion about the importance of wildlife crossings in the state. 

Three fifth grade students from FernLeaf Community Charter School in Fletcher delivered letters to the governor advocating for wildlife safety along North Carolina’s highways.

Held at the Western Office of the N.C. Department of Natural and Cultural Resources, the meeting was also attended by representatives from National Parks Conservation Association, The Wilderness Society, Defenders of Wildlife, Southern Appalachian Highlands Conservancy, Great Smoky Mountains Association, Rocky Mountain Elk Foundation, The Conservation Fund, N.C. Wildlife Federation and Wildlands Network — as well as N.C. Wildlife Resources Commissioner Brad Stanback, Secretary Reid Wilson of the N.C. Department of Natural and Cultural Resources and other key figures in the wildlife-crossing work.

Safe Passage facilitator Jeff Hunter began the meeting by introducing the coalition and its mission, then turned the spotlight over to the group’s scientists and researchers, who presented the data that’s been collected and explained how that data will be used to drive decisions about future wildlife crossing locations. 

From left to right: Hugh Irwin of The Wilderness Society; Bill Holman of The Conservation Fund; Brad Stanback of N.C. Wildlife Resources Commission; Christine Laporte of Wildlands Network; Tanya Prater from FernLeaf Community Charter School faculty; Ben Prater of Defenders of Wildlife; Nikki Robinson of Wildlands Network; Alexis Hinchliffe of FernLeaf Community Charter School faculty; Joy Mast, Elsa Rule and Cailee Montague, students of FernLeaf Community Charter School; Governor Roy Cooper; Hanni Muerdter of Southern Appalachian Highlands Conservancy; Liz Hillard of Wildlands Network; Jeff Hunter of National Parks Conservation Association; Secretary Reid Wilson of N.C. Department of Natural & Cultural Resources; Aurora “Rory” Wynne, intern of National Parks Conservation Association; Manley Fuller of N.C. Wildlife Federation; Steven Dobey of Rocky Mountain Elk Foundation; Emma DuFort of Great Smoky Mountains Association; Steve Goodman of National Parks Conservation Association. Photos by Jerry Greer, courtesy National Parks Conservation Association.

The three students then presented letters from their class, which were drafted during a project-based learning module about the impact of roadways on wildlife and how wildlife crossings can keep both people and animals safe. Over the course of the lesson module, hosted by Defenders of Wildlife and the Safe Passage Fund Coalition, students spent time reading “A Search for Safe Passage,” published by Great Smoky Mountains Association, and enjoyed a field trip to the Pigeon River Gorge to see firsthand how the Safe Passage Fund Coalition is working to make this section of Interstate 40 safer. 

“‘A Search for Safe Passage’ was written to engage the next generation — those who may inherit this work in the next 15-20 years — in environmental advocacy.”

— Emma DuFort, illustrator of “A Search for Safe Passage,” who spoke about the book and its message for young people at the June 2 meeting

They also learned the basics of advocacy and how to use social media to share important messages with the world. As part of their advocacy efforts, many of the students wrote letters to the governor asking for support for wildlife crossings locally and across North Carolina.

Following this presentation, the group continued engaging Gov. Cooper in thoughtful discussion, exploring the science behind wildlife crossings and examining the potential for crossings in the state. The group also emphasized that North Carolina could become a leader for this type of work in the Eastern United States, elevating the state’s profile on a national level by improving safety for travelers through progressive, science-driven crossing designs — and the governor voiced his enthusiastic support.

The students present their letters, and those from classmates, to Gov. Cooper.
NPCA’s Steve Goodman emphasizes to Gov. Cooper the evidence-based approach to this work.
NPCA’s Jeff Hunter greets FernLeaf Charter school students and faculty.
N.C. Wildlife Resources Commissioner Brad Stanback speaks to Gov. Cooper about Safe Passage: The I-40 Pigeon River Gorge Wildlife Crossing Project.

In the News: Smoky Mountain Living interviews Safe Passage’s Jeff Hunter

In February 2022, Smoky Mountain Living magazine published “A Conversation With the Smokies’ Wildlife Crossing Guard,” an interview with Safe Passage facilitator and National Parks Conservation Association senior program manager Jeff Hunter.

In the article, Hunter spoke with reporter Holly Kays on wildlife crossings in the Smokies, as well as the work of Safe Passage: The I-40 Pigeon River Gorge Wildlife Crossing Project.

“Interstate 40 opened in the gorge in 1968, and at that time the bear population was probably a quarter of what it is today — if not less — and there were no elk on the landscape,” Hunter said in the interview. “Today we have a growing bear population and a growing elk population that’s on both sides of the highway.”

Hunter went on to describe the increase in mortality rates along this stretch of interstate, as well as the work being done to mitigate this increase, then added: “The park is big, but wildlife doesn’t recognize the boundaries. So we have to work outside the boundaries if we’re going to make an impact.”

To read the full interview in Smoky Mountain Living, click here.