Protecting the Natural Sounds and Night Skies of the Great Smoky Mountains National Park

In Cover Stories by Élan Youngleave a COMMENT

Before I became a parent, I traced in green highlighter roughly two-thirds of the official trails on my now out-of-date trail map of the Great Smoky Mountains National Park, worn thin in the creases from more than a decade of use. From all those hikes, it’s the memory of particular natural sounds that holds the most power over me, able to catapult me right back into a high-elevation forest with wind rustling the treetops or next to a rushing stream lined with boulders softly furred with moss.

The first time I heard the eerie flute-like call of the wood thrush on Cucumber Gap trail near Elkmont, the world stopped. The spring ephemerals were on the verge of blooming, and the sound conveyed the essence of life awakening from winter. Spring was suddenly not a season, but now a process—one that was happening around me and also included me as a participant rather than simply the observer I had only ever been before. It was the wood thrush’s call that released me from my other self—the one with the chatterbox mind. I was momentarily transported, yet simultaneously more present: aware of slanted light, the rhododendron-lined path, and the sense that the impersonal woods had been transformed into an intimate space. I never saw the bird, but it had managed to stir in me something I’d not experienced often, nor could sustain: a greater sense of belonging, not just to a place, but to a specific moment in time.

Lightscapes, or night skies unpolluted by light, are equally important resources in allowing transcendent experiences in nature. I’m hardly the only one who has watched meteors trace arcs like flaming arrows shot from invisible bows from atop Mt. LeConte, which at 6,593 feet is the third-highest peak in GSMNP and is often blanketed in fog. However, because I also know the flat, muted skies of cities, each truly dark sky I witness is nothing short of a special occasion. But many urban dwellers have missed out on the kind of natural nighttime darkness that allows them to see more than a few bright stars. According to the International Dark-Sky Association, the U.S. population has grown at an average rate of 1.5 percent annually, while the amount of outdoor lighting in use has grown by about 6 percent per year. Now, eight out of 10 kids born in the U.S. live where they can never see the Milky Way. But it only takes one clear, brilliant night sky to change someone’s life. The park has on occasion provided inner-city kids visiting Great Smoky Mountains Institute at Tremont their first chance to gaze into starry depths.

As the National Park Service celebrates its centennial with much fanfare this year, the agency is also taking a sobering look at the next hundred years of management to protect its resources for future generations. While conserving flora and fauna has long been commonly understood as one of the missions of the NPS, fewer people know that the agency must also protect natural sound and dark-sky resources from the encroachment of modern life—yet without any of the authority of a regulatory agency outside its own boundaries.

For now, the Smokies are still one of the darkest places in the eastern U.S., and there remain many places where hikers can escape the sounds of revved engines. However, future generations stand a strong chance of losing an experience that so many Smokies’ visitors have taken for granted since the national park was chartered in 1934: The ability to find peaceful solace and refuge from the city with unimpeded natural sounds and a heavenly glimpse at the Milky Way overhead. Fortunately, NPS isn’t sitting idle on these issues. It’s researching the impacts of the encroaching world and working with nearby communities in efforts to make smart development decisions, curb the proliferation of light pollution, and hopefully sustain the natural resources that draw millions of people to the Smokies and help fuel many local economies.

Sounds of Silence
COVER_0630_Scott1Courtesy of Scott McFarland

NSNS specialist Scott McFarland teaches elementary and middle school students about the field of acoustic ecology and one method for collecting field recordings.

If there’s anyone who knows whether trees that fall in the Smokies make sounds when no one is around to hear them, it’s Scott McFarland, a specialist with the park service’s Natural Sounds and Night Skies (NSNS) Division, whose Southeast Region office is based at GSMNP (see sidebar below). Recording the park’s soundscapes is a job he’s well suited for as both a biologist and engineer, able to work efficiently to solve just about any technical issue that arises. His office at Twin Creeks Science and Education Center shows many signs of the engineer: a dozen or more red and black wires sprouting from battery boxes, and a large durable plastic briefcase with the field equipment he’ll set up today. It contains a sound meter, microphone, tripod, lithium iron phosphate battery, and cables.

In 2006, researchers used similar equipment to record natural ambient sound at seven locations in the park. Porter’s Creek went over its natural decibel range the least often, and Cades Cove, not surprisingly, went over its natural decibel range the most often. Over the next year, these boxes will record all of the 2006 locations again, plus a few new ones. With this data, he’ll be able to accurately assess the park’s soundscapes, to see if noise encroachment has grown louder over the past decade, and in turn help him develop recommendations for management. Data collection in Cades Cove will run through January 2017, and he hopes to wrap up the next phase to begin outreach and education to the community in late 2017 or early 2018.

“Even if the data collection was complete, there’s not yet a mechanism for comparing it to other national park units,” McFarland says. “However, initial data from Cades Cove shows that it has reached acoustic energy levels 20 times greater than some remote locations in the park.”

One of the new locations he’ll record is Bone Valley, the area furthest from any road. To get there, he’ll backpack in 65 pounds of sound equipment in addition to his personal gear. For today, at least, we’ve got an easy drive to Cades Cove where he’ll install a sound unit that will record continuously for one year from its hidden location off of Spark’s Lane. After each new location is recorded—most only needing one month of audio—the data is sent to Colorado State University where five to 10 students in a listening lab will get college credit for analyzing it.

Even with much yet to learn about the state of the park’s natural soundscapes, noise pollution elsewhere has already proven to be damaging to humans and animals. The World Health Organization reported the effect of noise pollution on the population in western parts of Europe and found that at least one million Healthy Life Years—a European public health metric used as a measure of economic productivity—are lost annually from traffic-related noise.

“Noise impacts the entire community,” says Jeff Titon, a retired ethnomusicology professor at Brown University and current Basler Chair of Excellence for the Integration of the Arts, Rhetoric and Science at East Tennessee State University. His career has focused on the role that sound plays in the shared environment. “Noise interference from airplanes, trucks and other vehicles, chainsaws and construction, adversely impacts the way all the creatures (humans included) communicate with each other in that environment. Sounds are directly related to ecosystem health.”

In the 1990s, GSMNP visitors were often rattled by the sound of low-flying air tour helicopters, which some residents experienced as a near-constant nuisance. What began as citizen complaints eventually contributed to a state law that prohibited air tours from using a runway or heliport any closer than 9 miles from the national park boundary. Since states do not have jurisdiction over air flight, which is regulated by the FAA, the state law could not prohibit flights over the park, but it could regulate the land used by air tour operators. The state law restricting heliports to 9 miles from the boundary prevented the state from interfering with the FAA’s jurisdiction over the Sevierville airport, which is 10 miles from the boundary.

Later, the National Parks Air Tour Management Act of 2000 amended federal aviation law to implement a framework in which commercial air tour operators near national parks can be managed. The state law’s 9-mile requirement for heliports also means that it is more expensive for tours to travel to the park, and the ones that do fly overhead are not there as long.

Scott McFarland has set up multiple sound recording stations throughout GSMNP, such as this one at Bullhead Trail. Courtesy of Scott McFarland

Scott McFarland has set up multiple sound recording stations throughout GSMNP, such as this one at Bullhead Trail.

Instead, today’s most human-generated noise in the mountains comes from motorcycles stripped of manufacturers’ mufflers. McFarland is quick to point out that the NPS has nothing against motorcycles that bear the manufacturers’ tailpipes, which have been engineered for sound reduction. Sometimes McFarland’s work takes him to busy roadways where he’ll set up a station with a sign that reads vehicles’ decibel levels. It’s a conversation starter to talk to people about the issue of noise, and he’s met motorcyclists who are unaware and sometimes alarmed that the rumble of their bikes might be audible 10 miles away.

During the 20 minutes in Cades Cove it took McFarland to set up the sound station, 10 airplanes flew overhead, or so he told me. Since I am hard of hearing, I couldn’t catch them all, but mainly I wasn’t paying attention. This made me realize how conditioned I am to hearing planes in the distance as background noise. Back in the office, he’d shown me a map of the U.S. bearing so many lines that all but a few outlying cities were blotted out. It looked more like an Etch-a-Sketch drawing than a map. This was the FAA’s flight path map. As I stood in Cades Cove, I understood firsthand the correlation between an abstract concept and a living, breathing soundscape.

The many lights of Gatlinburg in the Smoky Mountains.Sean Pavone

The many lights of Gatlinburg in the Smoky Mountains.

Hello, Darkness

Like soundscapes, lightscapes can incorporate cultural light sources, such as candles, and may be integral to historical places. Also, like human-generated sound that distracts attention away from the natural scene, light that intrudes into a nighttime scene amounts to light pollution.

Flagstaff, Ariz.—the city nearest Lowell Observatory—has led the global dark-sky movement with help from the International Dark-Sky Association (IDA). After years of debate around the issue, Flagstaff became the first place in the world to gain IDA status in 2001. Globally, 57 communities, parks, reserves, sanctuaries, and developments of distinction have met strict requirements to gain various levels of IDA status, a certification that increases both protection and awareness of night-sky resources. McFarland says he hopes the Smokies will soon join the list, as he is now seeking IDA status for the park.

Night-sky darkness is measured using the Bortle scale, a nine-level numeric scale that quantifies observability of celestial objects and the interference caused by light pollution. Bortle Class 1 skies are the darkest skies on Earth, and in the U.S. they only exist in western states. On the opposite end are Bortle Class 9 skies, which are inner-city skies. McFarland says that GSMNP has a predicted Bortle Class 4 throughout most of the park, but it can hit Class 3 in the southwest corner of the park. However, in the northern portions of the park, the Bortle Class can reach 5-6 due to lighting from nearby communities.

“Preserving dark skies isn’t necessarily about the environment, and it doesn’t have to come at the cost of economic development,” says John Barentine, program manager for IDA. “Fundamentally, it’s about being a good neighbor. Respect for one’s neighbors means being considerate with the use of one’s own property, whether commercial or residential. By simply containing light at night to that property, using the right amount for the task, and being mindful of the hours of night it’s in use, we can have dark skies, good relations among neighbors, and the right conditions for growing business opportunities.”

Pro-dark sky should not be mistaken for anti-development. According to the Texas Tribune, when the owner of Pioneer Energy Services, a San Antonio-based oil company, was approached about helping to protect the sky near McDonald Observatory by adjusting the lighting to one of his rigs, he became a convert. Not only was the owner interested in protecting the darkness of the West Texas night sky that had brought him personal fulfillment, but it also turned out that using more focused lighting, along with warmer-spectrum LED bulbs, helped improve worker safety and saved his company’s energy costs.

Additionally, dark-sky tourism, also called astro-tourism, is gaining popularity as people seek immersive dark-sky experiences found in relatively few places, and which presents an economic opportunity for the Smokies. Even average tourists are pursuing places where the authentic outdoors speaks for itself, which is the message suggested by “The Peaceful Side of the Smokies” campaign promoted by Blount Partnership.

Adjacent to Big South Fork National River and Recreation Area (about 75 miles northwest of Knoxville) is the Pickett State Park and nearby Pogue Creek Canyon State Natural Area, also known as Pickett-Pogue, which is the only place in Tennessee with IDA designation. One reason it succeeded in this effort was by securing broad support from surrounding municipalities that instituted regulations to ensure its long-term protection. This sort of community-wide support is usually the hard part.

Of all the IDA-certified places on Earth, only 14 are communities. Barentine says it’s harder for communities than parks to gain IDA status because coordinated participation from local governments is essential. However, even communities that are not seeking IDA status ought to still take care of their night sky assets, an argument made by Bernard Arghiere, a resident of Asheville who worked with the community to adopt what he says is a much improved lighting ordinance. As then-president of the Asheville Astronomy Club, Arghiere was an avid stargazer himself, but he found broad support surrounding issues of night blindness, glare, and light trespass.

When he took up the issue, the number-one offense to residents who complained to city staff was the prevalence of dusk-to-dawn lighting. These lights are strong, producing almost 10,000 lumens, which is the equivalent of six 100-watt bulbs clustered together. They are also unshielded and mounted on a tall pole. The intensity and lack of focus means they spill light upward into the sky and also onto neighboring properties. The city ended up banning all new dusk-to-dawn lights and phased out existing lights within five years of the new ordinance.

“Streetlights are more difficult to regulate because of all the jurisdictions involved,” notes Arghiere. Even still, he helped Asheville adopt stricter standards for streetlights rated greater than 4,300 Kelvins, the metric used to rate bulb color temperature. (The higher the Kelvin rating, the bluer the light and the worse for the night sky.) The city of Asheville was going to purchase 6,200 Kelvin LEDs, but Alghiere looked at studies from municipalities in San Francisco, Portland, Seattle, and Los Angeles, and found that all had rejected the same bulbs because they were too bright, emitting more light pollution than was necessary. He showed this to Asheville’s City Council and they changed their order.

Not every city has dark-sky advocates organizing around community lighting issues, but areas that benefit economically from a national park or wilderness area have more reasons to be concerned about light pollution. As a longtime advocate for national parks, Don Barger, senior regional director for the Southeast Regional Office of the National Park Conservation Association, often speaks eloquently about what he perceives is the highest value that a dark sky can have on human beings—a sense of place that is palpable to this park and to this region. But he notes that it doesn’t end there. With the incremental loss of the dark sky, we may risk losing touch with our sense of place on a grander scale.

“We’re essentially losing our sense of place in relation to the universe,” he says. “If we want our children to be able to reach for the stars, they have to be able to see them.”

A view of the Milky Way from Clingmans Dome in the Great Smoky Mountains National Park—one that can’t be seen in more well-lit populous areas.Appalachianviews via Dreamstime

A view of the Milky Way from Clingmans Dome in the Great Smoky Mountains National Park—one that can’t be seen in more well-lit populous areas.

Stars at the End of the Tunnel

Because the NPS is not a regulatory agency, it must work to gain support of the community to see changes. Within the next few years, McFarland hopes to begin the outreach to the surrounding communities through public presentations and conversations with local officials and citizens to help build awareness for natural sound and night sky protection.

“Getting the word out and educating people about the importance of protecting night skies and natural sounds for ourselves and wildlife is equally important to the scientific measuring and monitoring,” he says. “Noise and light pollution, just like air pollution, are not things that can simply be fenced out of protected areas. Rather, preserving these resources takes effort both within the park boundaries and collaboration from surrounding communities.”

Before making management recommendations to protect the park’s lighting, McFarland will first request a park-wide light audit in which every light bulb, fixture, and automatic lighting schedule will be evaluated. After all, the park can’t reliably recommend changes without first doing a full inventory of its own contribution to light pollution and making fixes. Eventually, this process will result in best practices and recommendations for the community with specific guidelines. For now, the NSNS can only offer general guidelines for sustainable lighting. (See info box below.)

According to IDA, lighting has become more energy efficient, but we are also a society that is using more and brighter lighting at night than we used to. Parking lots, even empty ones, are lit five to 10 times more brightly than they were 25 years ago. We’ve been conditioned to equate lighting with safety, but the IDA is following studies that suggest that increased brightness only increases the perception of safety. Furthermore, as air pollution increases, it exacerbates light pollution by refracting light. Meanwhile, the reddish-orange glow from Knoxville, and even Atlanta, burns on in the Smoky Mountain horizons.

In 2007, the Blount County Planning Commission took a proactive stance on regulating outdoor lighting by passing an amendment to zoning regulations. It was part of a larger discussion of design standards for commercial developments and addresses 13 requirements.

“County decision makers realized that there would continue to be pressure for commercial development along our main highways in rural areas,” says John Lamb, director of the Blount County Planning Department. “Commercial lighting stands out in less dense, rural areas, and a decision was made to address the issue with new regulations.”

Indeed, the regulations mitigate extra lumens (the unit of light measurement) from reflecting into the atmosphere by requiring that structures greater than 1000 lumens (about the brightness of a floodlight) to be mounted facing the ground with no upward angle to minimize scattering of light.

The city of Maryville adopted very similar standards several years earlier. The only difference is that the county standards limit the amount of light “trespass” at a property line to one-half foot-candle, while the city standards allow one foot-candle. (A foot-candle is the amount of illumination given by one candle-powered light source at a distance of one foot.)

Whether these regulations will be enough to reduce light pollution as development creeps toward the park along Highway 321 or the proposed (and controversial) Pellissippi Parkway (I-140) extension, is unclear. Big-box stores tend to shine a lot of cooler-spectrum light over empty parking lots, and the community is already bracing for the potential loss of a drive-in movie theater due to light trespass from a planned Walmart nearby (as reported in the Mercury last year).

Based on his cursory review of these regulations, Barentine, with the IDA, thinks stricter measures would be in order to obtain IDA Community status, which takes political will and coordination. With future development that doesn’t further restrict lighting through proper bulbs and housings, the Bortle Class on the northern edge of the park could continue to increase and threaten GSMNP’s ability to gain or maintain IDA status.

However, a dark-skies initiative could potentially enhance the results of a national marketing outreach for The Peaceful Side of the Smokies. Kim Mitchell, tourism director for Blount Partnership, agrees that a long-term commitment to protecting the park’s assets is an important part of the area’s economic vitality.

“Our goal is to always protect the integrity and beauty of the GSMNP,” she says. “An excellent example is the annual Synchronous Fireflies experience. This event, which is extremely popular, is now regulated to help ensure the experience is not only authentic and enjoyable for our guests, but also continues to protect the natural environment in which this event takes place. Our responsibility is to protect the lands and wildlife for the next generation no matter what the cost.”

COVER_0630_ClingmansNightSkycourtesy National Park Service
The Forever Business

It’s too soon to say what the park’s soundscapes and lightscapes will be like by the NPS’s bicentennial a century from now, but noise has already proven to be difficult to define, let alone regulate. Additionally, the IDA believes by 2025 no dark skies will exist in the U.S. Without widespread cooperation among communities in the foothills of the park, the challenges that it faces—already the most-visited in the entire NPS system—could continue to grow. The NPS and its employees are, as McFarland put it, “working in the ‘forever’ business,” striving every day to protect for future generations what public pressure might inadvertently destroy.

This work requires a long-term view, according to GSMNP Superintendent Cassius Cash.

“We don’t always think about the role natural sounds and dark night skies play in a park experience,” he says. “But the captivating sounds of mountain streams and birds are an important part of what personally connects us to landscapes. As we enter into the second century of service for the National Park Service, it’s critical that we preserve these resources for the next generation of visitors and the species that depend on sounds and light to communicate.”

When escaping to the GSMNP, it can take time for the noise of contemporary culture—audible and digital—to wear off, which may be reason enough for visitors to stay overnight in the backcountry. Even though I’ve gingerly tucked away my aging park map until I can return to the trails without the demands and logistics of early parenthood, I am comforted by the thought that the same woods will be there waiting for me when I do. Or will they? Knowing how challenging it might be to protect these precious resources, I wonder whether my son will grow up to be able to experience the park as I have, or whether he’ll be able to grasp what was lost if he can’t experience a dark sky firsthand or be alone with the sounds of nature free of the sounds of engines.

As a regular hiker, I learned to trust that if I stuck with it long enough, eventually I would become acutely attuned to my surroundings as the concerns of the busybody world were sweated out of my pores. Spending time in nature without the distractions of unnatural sound and light has long been part of American wilderness ideal. Nature’s role in awakening the senses is part and parcel to our ability to make new discoveries and create works of genius. Whatever we may individually seek to gain by protecting natural sounds and night skies, it’s certainly much bigger than can be seen or heard. 


Sound, Light, and the National Park Service’s Mission

Soundscapes and lightscapes function as both nice-sounding words and technical terms. The park service defines soundscapes as the human or animal perception of acoustic resources, which includes both natural sounds like wind, water, and wildlife, as well as cultural and historic sounds such as battle reenactments and tribal ceremonies. It defines lightscapes as night-sky resources and values that exist in the absence of human-caused light.

The Park Service Organic Act of 1916, on which the National Park Service was founded, requires that the agency care for the public lands and “…leave them unimpaired for the enjoyment of future generations.” In other words, the national parks are meant to be preserved and they are also meant to be enjoyed. It’s the word “enjoyment” that is of particular interest to many, including Don Barger, senior regional director for the Southeast Regional Office of the National Park Conservation Association (NPCA). He remembers hearing a talk by former NPS director Roger Kennedy who said, “Enjoyment as contemplated by the Organic Act means informed delight, not feckless merriment.” Barger explains that visitors ought to be enjoying unimpaired resources.

“If the resources are impaired, then the NPS has failed not only the physical responsibility to the resources, but it has also failed the responsibility to visitor experience,” he says.

However, the impetus to protect these assets could just as easily be driven by matters of human and animal survival. While research from the World Health Organization, among others, connects peaceful sounds and nighttime darkness with decreased anxiety and overall wellbeing in humans, for wildlife they are matters of survival. Wildlife rely on natural sound and patterns of light and dark for navigation, to cue behaviors, or to hide from predators. When these are disrupted, it changes the way the entire ecosystem functions. But it’s only in the last 15 years that the park service has responded to the need to protect national parks from encroaching noise, and more recently light.

In 2011 the NPS established its Natural Sounds and Night Skies (NSNS) division, and now its team of roughly 20 employees operate out of Fort Collins, Colo. They are responsible for various aspects of protecting natural sounds and night skies in all 400-plus park service units, but only one critical staff member is dispatched in each of the three regions across the U.S.: Alaska, Pacific West, and Southeast—the office for which is headquartered at the Great Smoky Mountains National Park.

Sustainable Lighting General Guidelines

The NPS’s Natural Sounds and Night Skies division recommends the following guidelines for preserving the night sky.

1) Light only if you need it.

2) Light only when you need it.

3) Aim light where it is needed.

4) Use appropriate color spectra. (Amber bulbs, typically below 2700 Kelvin)

5) Use the minimum amount of light necessary.

6) Choose energy efficient lamps and fixtures.

“Using the proper housing puts the light where it is needed instead of upward and outward, which is just wasted energy and will allow for lower wattage bulbs to be used,” says Scott McFarland, NSNS Division Specialist for the Southeast Region. “Amber lighting is also key, as light on the bluish-white end of the spectrum contributes to glare, hampers nighttime visibility, and scatters further into the air.”


• An earlier version of this story said sound data is sent to Colorado State University where it’s analyzed by more than 500 students—it’s actually five to 10 students.

• The National Parks Air Tour Management Act of 2000 does not outright prohibit commercial air tours over NPS units, but it does provide a framework in which they can occur and be managed.

Élan Young is a freelance writer and editor living on the beautiful Little River in Walland, Tenn. She’s also a longtime board member for the Little River Watershed Association and an advocate for all things Smokies.

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