Foothills Parkway Statement

November 17, 2023

Great Smoky Mountains National Park
Foothills Parkway Section 8D Scoping
107 Park Headquarters Road
Gatlinburg, TN 37738.

The purpose of this communication is to provide input into the scoping study regarding the Great Smoky Mountains Foothills Parkway Section 8D, due November 18, 2023. This proposed new section would extend the Foothills Parkway within the existing NPS-managed corridor for 9 miles from Wears Valley to the Southbound Spur near Gatlinburg and Pigeon Forge, Tennessee.

The following comments on this proposed project are submitted on behalf of seven environmental organizations that are active in the southern Appalachian region: the Harvey Broome Group of the Sierra Club, WaysSouth, the Center for Biological Diversity, the National Parks Conservation Association, The Wilderness Society, Defenders of Wildlife, and the Tennessee Citizens for Wilderness Planning.

  • A full and current Environmental Impact Statement is required by NEPA for a project of this magnitude, complexity, level of controversy, environmental and social impact, and cost to taxpayers. The National Park Service should not have chosen to use an Environmental Assessment, or expected this choice would go unchallenged. 
  • The Draft EIS written for this project in 1992 should be made easily available to the public immediately. It clearly documents significant impacts to hydrology and water quality, extent of fragile, unstable karst and pyritic geology, proximity to a major geologic fault line, and a route through what is now a rapidly developing residential area. The proposed construction includes extensive cut/fill, a large tunnel, and ends at the former Gatlinburg city dump with unknown buried hazardous materials. 
  • A tremendous amount of new residential and commercial development has occurred in Wears Valley since the 1992 DEIS. Such development can drastically alter drainage patterns and slope stability. It has been over 30 years! Conducting a new EIS is critical to understanding how these new residents and alterations to the environment will affect and be affected by the proposed parkway. A state-of-the-art EIS would be the best way to minimize the harm imparted to our mountains and Tennessee residents. Further, the views touted as a value to the 'driving experience' are not of the Smokies; the views will be away from the Smokies and towards thousands of homes, overnight rental cabins, and commercial businesses. The parkway will in fact disrupt the view of the Smokies enjoyed by many of these residents.
  • Stability in the geologic formations involved in the construction is the most significant concern. It is important to note that this concern applies to both the construction and operational phases. These formations are the same as those in the Pigeon River gorge that borders the GSMNP, an area prone to rockslides that can close I-40 for months at a time, which then requires tremendous effort to repair. This section of I-40 was among the most expensive ever built in the US because of the instability of the subsurface geology. The entire area contains historical landslides and colluvium common to this region of the southern Appalachians. Page 69 of the 1992 DEIS mentions how important soil creep and land movement is in the areas proposed for construction, and in fact several catastrophic collapses have occurred on the Southbound Spur near where the proposed Section 8D would intersect. Most importantly, a ¼ mile long tunnel is being proposed in this location. The following excerpt from the DEIS (p. B-2) demonstrates the dramatic and problematic nature of the stability of the underlying geology: “A slump crosses the entire corridor on Buckeye Knob....The lower end that crosses the road centerline contains morphologic evidence of abundant lateral movement of water. Crossing this feature will require some slope stabilization if the toe of the slump is removed...Because of the platy character of most phyllite and siltstone coarse fragments, and the very high silt plus clay content of the soil, erosion problems will be especially severe.” The 1992 DEIS points to various locations where fill will be used, and where bridges will be built, and where culverts may be used. But these design plans may be fully undercut (pun intended) by a lack of understanding of the subsurface. Modern geophysical survey methods use greatly updated technology compared to methods used in the early 1990s. Subsequently, this geophysical data is used to build detailed 3D computational models of the configuration of the subsurface geology, i.e., formation boundaries, geophysical properties, folds, faults, bedding orientations, and cleavage orientations. Complex and capable models of the subsurface barely existed in the early 1990s and are certainly not evident in the 1992 DEIS that the Park proposes to rely on. Current technology MUST be used to inform the development of an EIS for this project.
  • The 1992 DEIS was prepared when all of Wears Valley used private wells for water, i.e., no public water supply, and today only the immediate US 321 corridor has a public water supply. The 1992 DEIS describes the karst groundwater system involving shallow soils, sinkholes, disappearing streams, and caves, and notes the considerable risk of contamination of the groundwater system due to the highway construction. As described above, modern geophysical technologies and computational models MUST be used to provide a current and state-of-the-art understanding of the subsurface geology. In particular, geophysical surveys can provide information on the depth of soil cover and the distribution and location of open fractures and cavities. The latest version of computational hydraulic models (which barely existed in 1992!) should then take the geophysical data and other information to predict existing subsurface flowpaths and residence times, and to predict how they might be changed by construction of the Parkway. A new EIS using the most updated geophysical and computational methods to enable understanding of underground groundwater flowpaths, and the effects of construction, is absolutely necessary. The EIS proposes to use “land bridges” – i.e., fill dirt – to cover areas of construction in karst landscape and prevent catastrophic karst collapse. Such activities need to be supported by modern, quality data. This is the standard method for highway planning in the 2020s, and it is the only way to protect residential water supply for the entire valley. We absolutely cannot rely on an antiquated understanding of the subsurface geology and hydrology to provide protection for Wears Valley residents and the environment. The Park will be responsible for the effects of construction, and this is a responsibility that should not be taken lightly.
  • The 1992 DEIS conducted a year-long survey to understand baseline groundwater and surface water flow and responses to storms, in terms of flow magnitudes and ionic concentrations. Given the vast changes over the landscape in the intervening 30 years, it is safe to assume that these baseline observations are completely irrelevant to today’s conditions. A new survey must be conducted in order to establish a baseline and then to determine the changes imparted by the parkway’s construction. Otherwise, the Park may find itself liable for a wide variety of changes in ground and surface water conditions, that may simply be an effect of the many changes in the intervening 30 years since the 1992 DEIS.
  • The acid-releasing Metcalf phyllite poses considerable risk to surface and subsurface water quality when it is penetrated during construction. Since 1992, tremendous advances have been made in nonintrusive geophysical methods, as described above. A new EIS should take advantage of these new technologies to better understand the distribution of the Metcalf phyllite. Then, a deep core collection activity should be conducted, followed by core analysis, to determine the acid-producing potential of formations which will be disturbed by construction of the road. This is the only way to truly minimize the potential for acidification of ground and surface waters during construction through the Metcalf, and it is unwise to proceed with route planning and construction without first conducting a detailed core survey. Encountering acid-producing formations during construction is far too late; the knowledge of the formations must be used to plan the route. In other words, geophysical surveys and core collections need to inform route planning, and therefore they must precede publication of a new DEIS. Additionally, this kind of data is required to properly utilize the rock debris created by the road construction, i.e., to understand whether rock debris should be transported to a landfill, used in the road without remediation, or used as fill with remediation involving intercalation with limestone to neutralize the acid-producing capacity. Note, these issues can add tremendous cost to construction.
  • The potential for wildlife-vehicle collisions needs to be considered and mitigated in the updated EIS. Up to 200 human deaths, 26,000 injuries, and $12 billion in damages are believed to result from wildlife-vehicle collisions per year in the US. A study was conducted in 2018-2020 along a 28-mile section of I-40 in the Pigeon River Gorge as part Safe Passage: The I-40 Pigeon River Gorge Wildlife Crossing Project tallied 140 bear, deer and elk deaths. Wildlife crossings are finally being considered during road construction and repairs in the eastern US to enable the movement of large and small animals including elk, bear, and deer, and to minimize wildlife-vehicle collisions ( Current examples include a “land bridge” at the Appalachian Trail crossing at Stecoah Gap in North Carolina, facilitated by WaysSouth and currently under construction; and a longer-term effort ultimately involving 5 bridge replacements with wildlife crossing infrastructure on I-40 in the Pigeon River Gorge, with one nearly completed to date. An updated EIS should involve biological surveys to understand key passage locations, key breeding locations, and enable their consideration under planning and construction. Impacts to bats, salamanders, cave invertebrates and associated cave flora and fauna should be evaluated, particularly those known to be endangered. Since this Parkway traverses karst landscape, surveys for these creatures are particularly important.
  • GRSM has been slow to recognize and address climate change in any meaningful way. Constructing a major highway to fulfill the outdated ‘purpose and need’ of recreational driving is a classic example of backward thinking influenced by the fossil fuel and construction industry. The existing Foothills Parkway combines with US 129 (aka The Dragon) as a destination for sports car and motorcycle clubs and individuals who enjoy high speed driving. Blount, Monroe and Sevier County EMS organizations are already stretched beyond capacity responding to accidents on NPS roads since the Park lacks sufficient staff to respond. 
  • This proposal is completely at odds with the Biden administration’s climate goals, particularly the Bipartisan Infrastructure Law, which seek to avoid a climate Armageddon unleashed by burning fossil fuels. The 5th National Climate Assessment, released THIS WEEK, demonstrates the complete scientific agreement regarding human-caused climate change, the risks to our country’s financial security, and the danger to our environment and precious spaces, like the GSMNP International Biosphere Reserve. We are surprised that the current Federal administration is considering this outdated and reckless proposal. The Park should reconsider its involvement and support for this project, and stop work immediately.
  • We believe there is one valuable alternative that could be reasonably achieved, if the project proceeds at all. An Alternative should be added to this scoping and planning process: the entire remaining Foothills Parkway right of way from Wears Valley to Cosby should be used for a multi-use hiking and bicycling trail. This Alternative would greatly reduce environmental destruction as well as maintenance and construction costs. The Virginia Creeper (VA) and Swamp Rabbit (SC) are examples of creative, healthy, profitable and environmentally sustainable tourism venues.

We thank you for the opportunity to comment on the GSMNP Foothills Parkway Section 8D. We are very pleased to have involved seven non-profit environmental groups active in the southern Appalachian region in preparing these comments. Comments are submitted on behalf of the 7 organizations listed below, and contact information is provided for each lead contributor. We hope our comments are helpful in your making an informed and careful decision about the future of this project.


Gerald Thornton, President
Harvey Broome Group of the Sierra Club

Melanie Mayes, Board Chair

Will Harlan, Southeast Director and Senior Scientist
Center for Biological Diversity

Olivia Porter, Southern Appalachian Landscape Project Director
National Parks Conservation Association

Jess Riddle, Senior Conservation Specialist, Southern Appalachia
The Wilderness Society

Nancy Manning, Executive Director
Tennessee Citizens for Wilderness Planning

Tracy Davids, Senior Representative, Southeast
Defenders of Wildlife