The trees that once grew on the lake floor are reminders of another time when Virginia's only natural mountain lake was doing a disappearing act. According to Roanoke College professor Jon Cawley, this ebb and flow pattern is normal for Mountain Lake. But vanishing completely is something it hasn't done in more than 200 years.
Cawley, a board member on the Mountain Lake Conservancy, finds the phenomenon interesting and thinks humans shouldn't tamper with the lake. But the hotel's management has seen reservations drop by more than 5 percent, and heard the grumbling about the mud-rimmed lake as the water deficit slips to 20 feet below normal. The working boat dock, and the blue lake that served as a backdrop for Patrick Swayze's romantic moves in the movie "Dirty Dancing," are now a brisk 10-minute walk from the stone hotel.
For four years now, Mountain Lake has been slipping away, draining down a hole in its bottom faster than rain and springs can replenish the renegade waters. How low will Virginia's only natural mountain lake go? When will this trend reverse? These are crucial questions to hotel general manager H.M. "Buzz" Scanland.
"We are at a stage where we will very likely have to help nature," Scanland says. He's in a quandary trying to figure out what to do without damaging the lake's ecological balance or spoiling its natural appeal.
Cawley, who did his doctoral dissertation on the lake's water system, says in the past a small earthquake usually plugged the hole enough so the lake refilled. Although the lake is full more often than not, Mountain Lake has been shrinking and refilling for at least 6,000 years, Cawley says.
"Mountain Lake has a unique valve system," he says. "It does the ebb-and-flow thing roughly every 75-100 years. The amount of water leaving through the hole is about the same, but, with a drought, less water is coming in."
As part of his research, Cawley had scuba divers explore the lake and has taken sonar readings of the entire lake bottom. He knows the main hole is a 3-foot by 15-foot gash in a fault line running directly under Mountain Lake. The hole breaks through about 20 feet of sandstone and shale into a natural pipeline Cawley believes resurfaces half a mile away at Pond Drain, the outlet that normally flows from the surface of Mountain Lake. Local legend posited the hole's existence long before Cawley's dissertation offered definite proof. Avery Dollinger, whose parents were caretakers of the hotel, heard stories of employees throwing mattresses, broken boats and other debris into the lake's deep end in the 1940s to stanch a leak. After a 1959 earthquake cracked the lodge fireplace, the lake reportedly rose nearly 20 feet in a few weeks.
Although no one living can remember a time when Mountain Lake didn't exist, historical records indicate the lake disappeared between 1751, when surveyor Christopher Gist discovered the "clear-water lake with its fine meadow," and a generation later. Early settlers salted their cattle in a wet depression between the ridges and named the area Salt Pond Mountain. Then, in the 1820s, the lake reappeared; early owner Henley Chapman reported trees standing beneath the clear water. Carbon-14 dating of the dead trees found as the lake recedes indicate some stopped growing even earlier—in the 1600s.
Plugging the main hole won't restore Mountain Lake, Cawley says. During heavy rains, the pressure differential occasionally causes water to gush up from the fissure, so a plug would likely be pushed out also. And even if the plug held, the lake is honeycombed with smaller holes and cracks, Cawley says.
Ideas to restore the lake have ranged from erecting a bottom liner on a frame ("You might as well add chlorine and paint the bottom blue," Cawley sniffs) to pumping water back into the lake from Pond Drain or wells. They started in July by pumping well water into the lake.
"But because it comes from the same source, we might be taking water away from the lake to put back into the lake," Scanland says.
Another possibility is to pump water from outside the Mountain Lake drainage basin.
Cawley questions whether anything should be done at all.
Mountain Lake is an early warning system for the Southern Appalachians, he says. He sees the lake in its natural condition as a gauge of climactic conditions and of the severity of acid rain. "The only pollution that comes into the lake comes through acid rain," he says. "We can see a significant difference in the lake's nitrites, ammonium and phosphates before and after a heavy rain.
Cawley thinks the resort should capitalize on the changes in Mountain Lake. "This is a unique time in the history of Mountain Lake," he says. "It's not likely to stay this way."
Each of these times corresponded with a global period of reduced solar output Cawley refers to as a "minimum" or "minimal." During these colder, drier times, the sun's magnetic activity in the form of sunspots was low or nonexistent. Solar output was less, by as much as 5 percent some years. Some scientists correlate crop failure, plagues and population unrest with these periods.
The last such period was the Maunder Minimum, named for the scientist who observed it. During this period between 1645 and 1715, the sun had a low radiance level, causing glaciers to advance, the canals in Venice to freeze, and crops to fail globally. A milder minimal, the Dalton Minimum; occurred between 1795 and 1820, when settlers reported seeing Mountain Lake as "Salt Pond."
Despite the May frosts this year, we are not now in a minimal, Cawley says. The sun is warm and sunspots are active. He predicts that Mountain Lake is not likely to empty soon, although it could get a little lower if left to its own devices.
• Mountain driftwood. It's worth a trip to Bob Evans' shop at Mountain Lake Hotel to see his gnarly new Knobbits with stones in their beards.
• Better birding. Virginia Tech professor Jerry Via, who leads bird walks for hotel guests, says the new, wide-open space around the lake offers more opportunities to spot birds in the trees. And killdeers, ground-nesters, have moved onto the former lake bottom.
• Finer fishing. The resort still adds 700 pounds of trout annually to its floating stock of trout, bass and blue gills, and now all fish are concentrated in almost half the space. Does it make better fishing? Let's keep it a secret, says a Covington, Virginia, angler who hooked two tagged trout in a single weekend, winning $400 in hotel services.
• Swimming pools. Mountain Lake has added two heated outdoor pools to compensate for the loss of the beach.
• New artistic perspective. Regional artists gathered lakeside in spring for a workshop. Their responses to the changing shoreline comprise a traveling exhibit, due back at Mountain Lake in late fall.