Yellowstone Loses Winter Tranquillity With Snowmobiles : Environment: As many as 1,500 of the vehicles race through the park daily, clustering around Old Faithful in a buzzing, smoky gridlock. The problem is worsening as thousands use the new Continental Divide trail.

Winter has always been the most serenely beautiful time to visit the volcanic wonderlands of America’s first national park.

Geysers and hot springs cast delicate veils of steam and ice crystals over forests and meadows. Amid these steaming marvels congregate many of the park’s 4,000 buffalo, innumerable deer and antelope and hundreds of migratory birds that use the warm streams as a comfortable winter resort.

The beauty isn’t likely to change. But nowadays, scratch the serenity.

From mid-December to mid-March, as many as 1,500 snowmobiles a day race through the park on more than 50 miles of well-groomed trails, clustering around Old Faithful in a buzzing, smoky gridlock and occasionally riding herd on hapless animals that also use the trails.

The problem rapidly worsens. This season has seen thousands more riders arriving on the newly opened 340-mile Continental Divide snowmobile trail, which starts in Lander, Wyo., traverses part of Grand Teton National Park and ends at Yellowstone.

A U.S. Park Service estimate of 140,000 winter Yellowstone visitors by the year 2000 was exceeded two years ago. Some now predict that 300,000 winter visitors a year will clog the park early in the next century.

What can be done? “We’re working with Grand Teton and with the neighboring national forests to look at what types and levels of winter use are appropriate,” said John Sacklin, Yellowstone’s planning chief.

“We’re looking at effects on wildlife, and this season we installed monitors for particulate and carbon monoxide emissions,” he said. “Grand Teton Park has commissioned a study on noise levels. We’re also hoping that the snow machine industry will get the message and get to work producing a Yellowstone-friendly machine that’s whisper-quiet and super-clean.”

For environmental groups, that is too long to wait.

“They simply don’t know what effects winter use is having on the park,” said Jeanne-Marie Souvigney of the Greater Yellowstone Coalition in Bozeman, Mont. “We’re calling for a moratorium, to limit rentals or concession permits until their studies are done. Otherwise, local communities will continue to build their economies on winter use, and it will be hard to go back.”

How dirty and noisy are snowmobiles? Critics like to quote a California study estimating that a thousand snowmobiles emit as much pollution as a million cars--a figure the industry hotly denies and nobody else confirms.

“Nobody was looking at snowmobiles before,” said Janet Cohen of the U.S. Environmental Protection Agency’s Mobile Source Program test laboratory in Ann Arbor, Mich.

“We’ve looked at other small-engine devices, such as lawn mowers and riding tractors, but snowmobiles are relatively few and weren’t considered a major contributor to air pollution in problem areas,” she said. “But we’re developing test procedures now. You can look for a proposed emissions standard in 1996.”

Visiting snowmobilers spend $40 million a year in Montana, said Jim Sylvester of the state’s Bureau of Business and Economic Research. About 75% of the money goes to West Yellowstone, a town immediately outside the park, where 18 local companies have invested in about 1,000 machines that each rent for about $70 a day.

“If they eliminate snowmobiles from Yellowstone, that’ll cut one-third of the town’s economic base,” said David McCray, 37, who manages Two Top Snowmobile Inc. “Snowmobile tourists spend a ton of money--between $200 and $300 a day for a family of four. And most of them come back saying it was the best day of their trip, even the best day of their lives.”

Watching squadrons of snowmobiles and their helmeted and visored drivers snake along Yellowstone’s snow-covered roads can seem like watching an army of mechanized aliens. But behind the visors are people like Linda Harris of Buford, Ga., sharing a brand-new rental machine with her husband, Jim, and son Nicholas, 5.

“I’ve never seen such beauty, unless you compare it to scuba diving on the Florida reefs,” she said.

Other drivers are sensitive to the noise and pollution, but see them as minor compared with the stress 3 million summer visitors place on the park with their caravans of cars and motor homes.

“Face it, there are lots of folks who just don’t have the time to go cross-country skiing to Old Faithful,” said the leader of an eight-member Midwestern family group. “It’s our park too, and this is the only way we can see it in winter.”

Ironically, the boom in snowmobiles has brought an unwelcome boom in Yellowstone’s buffalo population, which is literally bursting park boundaries.

Since 1966, Yellowstone has had a hands-off management policy, allowing the herd to range freely so that researchers can observe natural migratory patterns. Long, savage winters kept the population in check as weaker animals--the young and the old--found deep snows too much for them.

“Opening the park to winter visitors has removed the natural fence of snow-depth,” said Mary Meagher, a research biologist who has studied the buffalo herd for 30 years. “As a result, winter-kills have declined and the population has been inflated by at least 1,500 animals. We have screwed up the system royally.”

Whatever its faults, the snowmobile really does offer a high road to winter adventure. Returning from an exhilarating 50-m.p.h. park visit, an environmentally concerned rider summed things up this way:

“You just have to think of it as the machine you hate to love.”