Every day, about 2,000 cars and trucks cross a deep gorge using a bridge that is more than a million years old.
It’s not really a bridge, the Virginia Department of Transportation says of the Natural Bridge, a 215-foot-tall limestone arch carved by the forces of nature from the Rockbridge County landscape.
Although U.S. 11 runs across the top of the landform, VDOT does not own, maintain or inspect it regularly for safety the way it would an artificial bridge.
“The ‘bridge’ is a geological formation” that does not fall within the transportation agency’s purview, spokeswoman Sandy Myers wrote in an email.
But now that Natural Bridge is part of a state park, questions are being raised about whether the weight and vibrations from traffic might pose a threat to its structural integrity.
There appears to be no evidence of imminent danger. Still, as part of a long-term plan for the Natural Bridge State Park, there’s talk of closing the bridge’s arch to traffic and building a bypass that would route U.S. 11 around the northern perimeter of the park.
“The reason it’s even being talked about is the stability of the bridge, ” Lynn Crump, an environmental planner for the state’s Department of Conservation and Recreation, recently told a committee that is working on a master plan for the park.
“If you’re talking about something that you want here for generations in the future, you do have to consider this.”
Should it happen, closing Natural Bridge to traffic and building a bypass would be a long way down the road in the development of a master plan for Virginia’s newest state park.
The idea was embraced last week by an advisory committee that has met four times since the Department of Conservation and Recreation, which manages state parks, took over operation of the rock bridge that crosses Cedar Creek and 1,500 acres of surrounding land from a nonprofit organization that owns the property.
DCR is coordinating the master plan process, with input from local, state and federal officials, elected representatives, community groups and citizens with an interest in the bridge’s future. Once completed, the master plan will guide development over the next 30 years.
Meanwhile, park officials are keeping a close eye on a more immediate concern — falling rocks.
Last study followed fatality
On Oct. 23, 1999, a tour bus carrying a church group through Southwest Virginia to see the fall foliage made a detour off Interstate 81 to visit the Natural Bridge.
As 83-year-old Louise Cathy of Georgia stood under the limestone formation, a slab about six feet long and a foot thick became dislodged from the underside of the bridge and came crashing down onto a walkway.
The large rock narrowly missed Cathy, officials said at the time, but a smaller chunk struck her in the head and killed her almost instantly.
The walkway beneath the bridge was temporarily closed, and the property owner hired a team of rock stabilization experts to scale the walls for loose fragments and knock them to the ground.
To secure the unstable rock that remained, the team bored holes from the top of the bridge and lowered cables through them. The cables were attached to 30-foot bolts with metal plates at the end that were then pulled tight to serve as anchors.
As part of the same operation, geologists from Radford University were called in to evaluate the bridge’s stability — and whether it was compromised by vibrations from traffic along U.S. 11.
Seismic studies were conducted by two firms, one for VDOT and the other for the Radford geologists. Both detected vibrations adjacent to the highway.
“However, the magnitudes and actual effects possible from those vibrations could be the subject of much debate, ” a report from the evaluation stated.
The VDOT study found no harm to the bridge. But Radford University geology professor Skip Watts concluded at the time that the long-term effects of traffic vibrations on the bridge were not well understood and should be examined further.
A 23-page report of the evaluation recommended that the study be continued in hopes of shedding additional light on the question.
Watts, who is still at Radford, said last month that nothing else has been done to his knowledge.
“The question is how much [vibration] is enough over time to cause some deterioration, and that’s a question we never got a very good answer to, ” he said.
Watts said he has spoken to DCR officials about his study and is willing to take another look at the bridge. When Crump addressed the advisory committee working on the park’s master plan last Thursday, she said such a study is needed.
Yet no formal steps have been taken, in part because of funding questions.
Officials with the state’s transportation and conservation agencies said they were not aware of any inspections or evaluations of Natural Bridge that have been conducted since the 2000 study.
Paul Cooper, a principal with Retro Hospitality, which manages the Natural Bridge Hotel and adjacent caverns, said he believed a study was done in more recent years. But he was unsure of the details.
Cooper spoke to The Roanoke Times at the request of the Virginia Conservation Legacy Fund, a nonprofit organization that currently owns the bridge and surrounding property. Jennifer Bell, an executive with the organization, and its founder, Tom Clarke, did not return multiple calls over the past two weeks.
VCLF purchased the Natural Bridge property in 2014, shortly before it was slated to be sold at an auction, with plans to eventually donate it to the public for a state park. The organization struggled financially, and the state officials stepped in last year to restructure its loan and take over management of the land as a state park.
Cooper, who attended last week’s meeting, said he’s open to the ideas that were discussed.
“To us it’s an essential piece of tourism and the history of Virginia, and we have to do everything we can to preserve it for as long as we can, ” he said of Natural Bridge. “So it’s incumbent on all of us to study this and come up with some solutions.”
Daily inspections below
For years, the stretch of U.S. 11 that crosses Natural Bridge has been out of sight and out of mind — at least to the casual observer.
Visitors to the bridge cannot see the highway as they gaze upward from a trail that follows Cedar Creek under the limestone arch. From the top, wooden fences on each side of the road obstruct the view, and a chain-link fence topped with barbed wire prevents anyone from getting too close to the drop-off for a better look.
“I would say that 90 percent of the people [who visit the park] don’t know that there’s a road on top of that bridge, ” said Chris Wise, one of the organizers of Friends of the Natural Bridge, a community group formed in 2013 when the property was put up for sale.
“Every now and then, when a truck comes across, you hear the noise but you can’t see the truck, so it’s hard to locate where that noise is coming from.”
But when rocks tumble down, questions come up.
“Common sense would indicate that any vibration” from U.S. 11 traffic might loosen rocks at the top of the arch and cause them to eventually fall, the 2000 report stated.
At the time the report was written, rock falls were not uncommon. “The events appeared minor and were not perceived as any sort of a threat, ” the report stated. “It is important to recognize that Natural Bridge is part of a natural earth system and will continue to shed rock of various sizes from time to time.”
Today, park officials inspect the walkway and bridge every morning before visitors arrive, looking for loose or fallen rocks. In the colder months, when rocks are exposed to freezing and thawing, they might find something three or four times a week, said the DCR’s Jim Jones, manager of the park. During the summer, falling rocks are less frequent.
“Is it a natural degradation? Sure, there’s certainly that, ” Cooper said. “But in my mind, it does not help for there to be thousands and thousands of pounds of vehicles riding over the bridge.”
2,000 vehicles a day
The Natural Bridge is many things.
It is “the most sublime of nature’s works, ” said Thomas Jefferson, who purchased it from the King of England in 1774. It is a tourist attraction once considered one of the Seven Natural Wonders of the World. It is a local icon that gave Rockbridge County its name. It is a National Historic Landmark.
And, Watts said, “as far as I know, it is the only natural bridge in the world that has a highway going over it.”
The part of Natural Bridge that serves as a vehicular bridge is about 90 feet long, varies in width from 50 to 150 feet and has a minimum thickness of 45 feet, according to a study of the formation by Edgar Spencer, a retired professor of geology at Washington and Lee University.
That study did not address the bridge’s stability or suitability for traffic.
VDOT inspects more than 21,000 bridges and structures across the state at least once every two years, according to its website. If there are issues with age, deterioration, damage or other concerns, more frequent inspections are conducted.
The part of U.S. 11 that crosses Natural Bridge does not meet the definition of a state-maintained bridge, Myers said.
With countless roads passing over underground caverns common to the region’s karst topography, it would be impossible to inspect them all as if they were a bridge.
“Many roads have a similar formation, ” as Natural Bridge, she said. But the open areas they cross are underground. There’s no way to see them unless there’s a sinkhole like the one that recently caused delays on I-81 in Augusta County.
In 2000, VDOT placed a weight restriction of 20 tons on traffic passing over Natural Bridge. But the limit can be waived when heavier trucks are diverted off the interstate in the case of an accident or other emergency.
According to traffic counts from 2016, an average of about 2,000 vehicles a day travel U.S. 11 between Exit 175, the southern Natural Bridge Exit, and Virginia 130 — a two-mile stretch that crosses the rock bridge. Trucks and larger vehicles make up about 5 percent of the total.
A bypass in the future?
In the 1930s, U.S. 11 was rerouted to cross Natural Bridge, according to the formation’s listing with the National Register of Historic Places.
But for “uncounted centuries” before that, the bridge was used as the best route across the steep valley walls that line Cedar Creek, said Jurretta Heckscher, a member of the Friends of Natural Bridge who has studied its history.
What started as a footpath traveled by Native Americans later evolved into a carriage road used by Colonial settlers.
“Nature has been very bountiful in fixing this bridge where it is, as if it was not there travelers would not have a road over the creek on account of the steepness of the hills, and would be obliged to go many miles around, ” a visitor from 1790 wrote in an account provided by Heckscher.
In more modern times, the route over Natural Bridge served as a key artery to a tourist destination that also included a hotel, restaurant, wax museum, mini-golf course, haunted house and other roadside attractions.
From I-81, the park is accessible from two Natural Bridge exits. Private owners have had little incentive to close the bridge to traffic, which would eliminate access from the southern exit that provides the faster way to reach their business.
A state park is different, with visitors more likely to drive the extra miles from the northern interstate exit to reach what is expected to be an out-of-the-way destination.
DCR has already encouraged the removal of some non park-like amenities, such as the wax museum and the nearby Foamhenge sculptures.
Under one alternative discussed last week, U.S. 11 from the south would be closed at the point it reaches the bridge — creating one of two entrances to the park. A bypass starting near Exit 175 would take traffic around the park and reconnect with U.S. 11 as it approaches the park from the north, where visitors would find a second entrance.
Another plan would keep the bridge open for park-related traffic, but with a bypass for through traffic and heavy trucks.
Any new road would have to go through VDOT’s lengthy application process. The agency recently suggested that DCR partner with Rockbridge County and the Central Shenandoah Planning District Commission to request a study as “a good first step in this process, ” Myers said.
So far, there has been no organized opposition to shutting the bridge down to vehicles.
“Our priority and concern is maintaining the integrity of the bridge, ” Cooper said. “And if that means it will make it a little more challenging for visitors to get there, then we’re prepared for that.”
So someday, Natural Bridge might become a bit more natural.