A new residential project in Marion County by Chattanooga developer John “Thunder” Thornton could be sitting on a “Swiss cheese” system of abandoned coal mine shafts, according to nearby residents.

Ronnie Kennedy, 68, of Whiteside, Tennessee, told Marion County commissioners in February the new River Gorge Ranch residential development atop Aetna Mountain — around 7,400 acres — was sitting atop a coal mine. Kennedy said he observed the facility’s operations for company family members in the 1980s.

Whiteside lies on the south side of the mountain. Kennedy was employed by the heir of the Pilot Coal Co. mine on Aetna Mountain to watch over operations for a few months after the owner died, he said in a follow-up phone interview. A family member gave Kennedy a box full of files, maps, documents and drawings to the mine, he said, claiming the developer turned them down when Kennedy offered to share.

Kennedy is one of several nearby residents concerned about the effect of Thornton’s development on local water, according to Paul Schafer, representative of the district on the Marion County Commission.

“That mountain is what some people call ‘Swiss cheese,’” Kennedy said. “I know about what’s up there because I’ve seen it.”

The old drawings and maps show

mine shafts extend a mile or more in some places, he said.

“I have received calls from residents of Marion County regarding issues of closed mines on Aetna Mountain,” Schafer told fellow commissioners in February. “In talking with residents and researching this issue, I first was told only surface mining was done on Aetna Mountain, and others said early on deep mining was also done. Most of the mines were closed prior to the federal and state government passing legislation on mine safety in the early 1950s.”

Schafer said the developer should make buyers aware if there are any problems.

During the February meeting, Marion County Attorney Billy Gouger said Kennedy and other residents have put the county on notice by formally raising the issue in a public meeting. He said the county Planning Commission, so far, has approved all lot plans submitted for building homes in River Gorge Ranch.

“Once the county’s put on notice of a potential issue, it has a duty to inquire and investigate,” Gouger told the commission in February. “I think that’s where we are now. I have no idea what all type of due diligence the developer would have done before purchasing or after purchasing the property, but typically, there would be some core sampling, geotechnical work done.”

Gouger said county leaders should first ask the developer to offer whatever information or studies on underground conditions.

“It should be shared with the County Commission and the Planning Commission,” Gouger said. “Whatever is shared with the county should be shared with the public as well.”

NEW REPORT

On Friday, Marion County Mayor David Jackson said materials from the developer were received and passed along to the Marion County Planning Commission, of which he also is a member.

“I gave it to the Planning Commission this past Tuesday evening,” Jackson said in a phone interview.

In a follow-up phone call, Gouger said the 25-page report speaks to the concerns raised by Kennedy and Shafer.

“What they provided was a geotechnical report done by an engineering firm a couple of years ago,” Gouger said. “It addressed strip mining. It addressed the general stability of the mountain itself.”

The report included results of sampling and testing performed to identify the types and conditions of rock formations and the formations’ stability, he said.

By the time county commissioners meet again March 25, they’ll all have a copy of the report, he said.

“To me, it answers the concerns,” Gouger said by phone. “The key language in our subdivision regulations is the ‘suitability of the land’ — if the land is suitable for development or not suitable for development. At this point, I can’t say the county or the Planning Commission has a rational or reasonable basis upon which to say that land is not suitable for development, especially given the report from the engineering firm.”

Thornton’s Thunder Enterprises, which acquired nearly 7,400 acres of Aetna Mountain near the former Hales Bar Dam through a series of property purchases in 2021, built a 1.6-mile road to the top of Aetna Mountain to open the ridgetop property for what developers expect will ultimately bring more than $1.5 billion of homes and mountaintop amenities to eastern Marion County.

In 2022, Thornton expected Aetna Mountain to double the amount of the investment in Jasper Highlands, a similar mountaintop gated community that Thornton developed during the past decade just 9 miles farther west along Interstate 24. A welcome center for the Aetna Mountain development, touted as potentially the biggest mountain development in Tennessee, is housed in a former fireworks store at Exit 161 in the Guild and Whiteside area.

In a statement, Thunder Enterprises spokesperson Albert Waterhouse, of Waterhouse Public Relations, said a geotechnical study shows the development sits on stable terrain more than 100 feet thick.

“River Gorge Ranch spent well over $100,000 on geotechnical engineering and testing conducted by Universal Engineering Sciences, a nationally recognized and award-winning engineering firm,” Waterhouse said in the statement. “The UES report shows the foundation of the lots are reinforced by rock with an approximate thickness of 120 feet.

“These findings in the report provide ample evidence of the stability of the lots, and in fact, it could support much larger structures than what is planned for our community,” Waterhouse continued. “Engineers stand by the report and have no concerns around the stability, which is also evident in the $12 million investment in the restaurant on the bluff that is well underway. In addition, the Marion County Planning Commission has reviewed and approved all the geoengineering and testing reports that were provided by the engineers at River Gorge Ranch.”

AETNA EXPERIENCES

During the February meeting, Commissioner Jim Cantrell, a former forestry worker, said he once saw a bulldozer sink up to the top of its tracks on Aetna Mountain. He said he thought the hole it dropped into was a well.

Gene Hargis, a county commissioner and detective for the Marion County Sheriff’s Office, agreed with Kennedy’s contentions about Aetna Mountain having mine shafts, but he also said those conditions exist elsewhere.

“This whole valley is a honeycomb underneath the surface,” Hargis said in the February meeting. “Every mountain, the Gizzard Cove where I live, had coal mines. Battle Creek had coal mines.

“It’s not just Aetna, it’s every mountain, even the valleys,” Hargis said. “You can go anywhere in Battle Creek and drive around in the fields at any time and see sinkholes that drop about 30 feet deep, half the size of this room — that goes into the aquifers. Same way with anything in the mountain — it’s honeycombed under all these mountains — it may not be just mines, but it’s cave systems, aquifers, and that stuff’s got to have somewhere to go and it’s going to filter down.”

Commissioner Dennis Rollins remarked his house sits on top of the ill-fated Grundy Mining Co. No. 21 mine on Whitwell Mountain, shuttered following a deadly explosion in 1981, and Commissioner Donald Blansett, of South Pittsburg, described water disappearing from a holding pond built as part of the town’s sewer plan a few years back.

“I go down one day, and I look, and there’s a big hole in the middle of my holding pond and no water in it,” Blansett said. “You’re right about the assessment that the land and the holes are not just in the mountains; they’re in the valley, too.”

The mountains surrounding Marion County have coal seams sought by miners years ago through deep mines and strip mines, Hargis said.

“There’s a coal seam up there that burned underneath the ground for years and years. I don’t know if it still is up there, but it burned several years up there,” Hargis said. “But when I first started working at the sheriff’s department, we’d be up there, and you could warm your hands (by the heated earth) in the wintertime.”

Considering Marion County’s extensive coal mining past and widespread development, several commissioners discussed the strong likelihood of old mine shafts being under private homes and other subdivisions on all the ridges surrounding the county.

“If every house couldn’t be built on a mine shaft, there wouldn’t be any houses left in half of Marion County,” County Commissioner Chris Morrison said, adding the degree to which mining intersects with residential development is farther reaching in Marion County than a single development.

Gouger agreed some level of mining has taken place on every mountain in the county.

According to the Tennessee Encyclopedia, industry and mining marked the county’s postwar history after coal was first discovered in 1852. In 1877, James Bowron and associates from England brought sufficient capital into the valley to develop the iron and coal industries. Coal mines opened in Whitwell, coke ovens operated in Victoria, iron ore came from Inman and smelters dominated South Pittsburg on the west side of the county.

Coal mining in Marion County largely met its demise with the deadly explosion in Grundy Mining Co.’s No. 21 mine in Whitwell in 1981 that killed 13 men, according to Chattanooga Times Free Press archives. Carson Camp, mining historian with the Sequatchie County Historical Association, said in a 2006 interview the No. 21 mine explosion marked the beginning of the end of the coal mining industry in the Sequatchie Valley.