Exeter Sinkhole inadvertently becomes subject of dye-tracing tests
December 15, 2021
In a recent photo (above) Bill Berg stands in front the large sinkhole on his property that opened up in his pasture in February of 2005. The sinkhole is now the subject of dye-tracing tests being conducted by volunteers with the Cave Research Foundation. Red non-toxic dye, buried by hydrologists alongside the public roadway northeast of the sinkhole in October, made its way downhill through groundwater to color the ever-present water in the sink a brilliant shade of reddish magenta two weeks ago. The volunteers are anxious to learn whether the dye will show up in Roaring River Spring when lab tests are returned in January. Photo by Sheila Harris.
Sheila Harris
Bill Berg and his wife Barbara own, arguably, the most notorious parcel of land in Barry County: the site of what’s become known as the “Exeter Sinkhole.” The erosion of soluble limestone and (or) dolomite bedrock created a dramatic opening in the earth – and a conduit to an underground aquifer - that began swallowing huge chunks of their prime pastureland in February of 2005. What began as a water-filled hole approximately ten yards wide expanded to a pit about ten times that large within a one-month period. As a result of shifting soil and erosion, its footprint has increased over the ensuing years, although it appears, now, to be relatively stable. However, the sinkhole is again gaining attention.
Two weeks ago, Bill Berg, a truck driver and rancher, reported that the water, a constant in the sinkhole, was bright red, unnaturally so. He invited me to come out and take a look, an offer I wouldn’t think of refusing since the sinkhole is now cordoned off from the public.
Although I had a general idea of where the sinkhole was located, I was surprised by the sharp descent along a narrow gravel road required to reach it. The sinkhole, I had always supposed, had opened on higher ground.
“The man from the DNR told me back in 2005 that it was really unusual to have a sinkhole of this size open up in a hollow,” Berg said.
“It’s large by any standards, though,” he added.
The gravel road ended abruptly at a piled-high berm with multiple strands of barbed wire stretching tightly across it. A game camera keeps a constant lens on both the fence and the steel gate which Berg opened to allow me passage to his property. From the gate, access to the sinkhole was by foot across some challenging Ozarks terrain: through a blackberry thicket, downward into a dry creek bed - which provided ankle-twisting opportunities for several yards, until we again ascended the side of the creek bed by grabbing tree roots and saplings. The walking became easier after a few more yards of undergrowth gave way to what I supposed was an old, grass-covered wagon trail. Nope, said Berg.
“It’s the remains of the old county road which used to run through here,” he explained.
Alongside that roadbed, on the south, the ground had crumbled away and formed a gradual descent into a vast crater, whose east and south surrounds could by no stretch of the imagination be called “sloping.” The sheer vertical walls, comprised mostly of fertile bottomland soil, were exposed by a low water level which lay approximately 30 feet below ground level. The water was, indeed, red. Red, with shades of magenta. While the dimensions of the sinkhole were longer (from the north to the south) than they were wide, their measurements stretched many hundred feet in both directions.
It was my first sight of the sinkhole which had caused a public stir, even some panic, when it first made its appearance in 2005. I haven’t been able to get out of my mind what I saw that day. The Biblical reference to the earth opening up to swallow Korah, Dathan and Abiram came easily to mind. While one can’t live in fear of a repeat performance, a sinkhole is an awe-inspiring natural phenomenon – and a relatively common one – in the karst topography underfoot in the Ozarks, a type of topography that Roaring River State Park employee, Kelly Koch, likens to Swiss cheese.
The Bergs had read that hydrologists were conducting ongoing dye-tracing tests in the area to determine the size of Roaring River Spring’s recharge basin, and had plans to give the hydrologists permission to inject dye into the sinkhole on their next visit, scheduled for January.
“When we saw the red water, we thought they’d jumped the gun,” Bob Berg said.
“Our first thought,” said Barbara Berg, “was that someone had come onto our property without our knowledge and poured dye into the sinkhole.”
A phone call to hydrologist Bob Lerch, a volunteer with the Cave Research Foundation, revealed that the dye was indeed his and co-volunteer Ben Miller’s.
“We didn’t place it into the sinkhole, though,” Lerch said.
“Our positive dye-tracing tests (to determine Roaring River Spring’s recharge area) have led us as far northwest of Roaring River Spring as Wayne,” Lerch said, “so the Exeter sink would be a natural next step in our progression outward from Wayne.
“When we were in the area in October,” Lerch said, “we didn’t have the names of the property owners, so we couldn’t ask them for permission to inject dye. We already knew from past observation, though, that water from the public roadway northeast of the sinkhole flowed downward toward it, so we buried about three pounds of non-toxic rhodamine red dye in the ditch.”
Lerch says he’s a little chagrined that their dye showed up in such a spectacular fashion and that the Bergs suspected he and his co-laborer, Ben Miller, might have trespassed.
“We’ll be happy to visit with them about our testing,” he said.
Although news of the sinkhole has tapered off since it first broke ground in February of 2005, Bob Berg remembers well the day a neighbor called to ask him what was going on his field.
“He told me, ‘You’ve got a hole out there with water churning up out of it,’” Berg recalled. “I decided I’d better go have a look.”
What Berg found was merely the beginning of a spectacle that drew throngs of curious area residents and news crews throughout the days and weeks to follow.
Story to be continued in the December 22 edition of The Barry County Advertiser.
Bill Berg and his wife Barbara own, arguably, the most notorious parcel of land in Barry County: the site of what’s become known as the “Exeter Sinkhole.” The erosion of soluble limestone and (or) dolomite bedrock created a dramatic opening in the earth – and a conduit to an underground aquifer - that began swallowing huge chunks of their prime pastureland in February of 2005. What began as a water-filled hole approximately ten yards wide expanded to a pit about ten times that large within a one-month period. As a result of shifting soil and erosion, its footprint has increased over the ensuing years, although it appears, now, to be relatively stable. However, the sinkhole is again gaining attention.
Two weeks ago, Bill Berg, a truck driver and rancher, reported that the water, a constant in the sinkhole, was bright red, unnaturally so. He invited me to come out and take a look, an offer I wouldn’t think of refusing since the sinkhole is now cordoned off from the public.
Although I had a general idea of where the sinkhole was located, I was surprised by the sharp descent along a narrow gravel road required to reach it. The sinkhole, I had always supposed, had opened on higher ground.
“The man from the DNR told me back in 2005 that it was really unusual to have a sinkhole of this size open up in a hollow,” Berg said.
“It’s large by any standards, though,” he added.
The gravel road ended abruptly at a piled-high berm with multiple strands of barbed wire stretching tightly across it. A game camera keeps a constant lens on both the fence and the steel gate which Berg opened to allow me passage to his property. From the gate, access to the sinkhole was by foot across some challenging Ozarks terrain: through a blackberry thicket, downward into a dry creek bed - which provided ankle-twisting opportunities for several yards, until we again ascended the side of the creek bed by grabbing tree roots and saplings. The walking became easier after a few more yards of undergrowth gave way to what I supposed was an old, grass-covered wagon trail. Nope, said Berg.
“It’s the remains of the old county road which used to run through here,” he explained.
Alongside that roadbed, on the south, the ground had crumbled away and formed a gradual descent into a vast crater, whose east and south surrounds could by no stretch of the imagination be called “sloping.” The sheer vertical walls, comprised mostly of fertile bottomland soil, were exposed by a low water level which lay approximately 30 feet below ground level. The water was, indeed, red. Red, with shades of magenta. While the dimensions of the sinkhole were longer (from the north to the south) than they were wide, their measurements stretched many hundred feet in both directions.
It was my first sight of the sinkhole which had caused a public stir, even some panic, when it first made its appearance in 2005. I haven’t been able to get out of my mind what I saw that day. The Biblical reference to the earth opening up to swallow Korah, Dathan and Abiram came easily to mind. While one can’t live in fear of a repeat performance, a sinkhole is an awe-inspiring natural phenomenon – and a relatively common one – in the karst topography underfoot in the Ozarks, a type of topography that Roaring River State Park employee, Kelly Koch, likens to Swiss cheese.
The Bergs had read that hydrologists were conducting ongoing dye-tracing tests in the area to determine the size of Roaring River Spring’s recharge basin, and had plans to give the hydrologists permission to inject dye into the sinkhole on their next visit, scheduled for January.
“When we saw the red water, we thought they’d jumped the gun,” Bob Berg said.
“Our first thought,” said Barbara Berg, “was that someone had come onto our property without our knowledge and poured dye into the sinkhole.”
A phone call to hydrologist Bob Lerch, a volunteer with the Cave Research Foundation, revealed that the dye was indeed his and co-volunteer Ben Miller’s.
“We didn’t place it into the sinkhole, though,” Lerch said.
“Our positive dye-tracing tests (to determine Roaring River Spring’s recharge area) have led us as far northwest of Roaring River Spring as Wayne,” Lerch said, “so the Exeter sink would be a natural next step in our progression outward from Wayne.
“When we were in the area in October,” Lerch said, “we didn’t have the names of the property owners, so we couldn’t ask them for permission to inject dye. We already knew from past observation, though, that water from the public roadway northeast of the sinkhole flowed downward toward it, so we buried about three pounds of non-toxic rhodamine red dye in the ditch.”
Lerch says he’s a little chagrined that their dye showed up in such a spectacular fashion and that the Bergs suspected he and his co-laborer, Ben Miller, might have trespassed.
“We’ll be happy to visit with them about our testing,” he said.
Although news of the sinkhole has tapered off since it first broke ground in February of 2005, Bob Berg remembers well the day a neighbor called to ask him what was going on his field.
“He told me, ‘You’ve got a hole out there with water churning up out of it,’” Berg recalled. “I decided I’d better go have a look.”
What Berg found was merely the beginning of a spectacle that drew throngs of curious area residents and news crews throughout the days and weeks to follow.
Story to be continued in the December 22 edition of The Barry County Advertiser.
The photo above shows the Exeter sinkhole during its initial opening stages in February of 2005. The county road, visible just beyond the sinkhole, was later closed to traffic due to potential instability. Submitted photo.
