YELLOWSTONE NATIONAL PARK -- In winter, Yellowstone National Park is a surreal mix of animals and elements, of coyotes and wolves, steam and snow. The earth's fiery breath rises from geysers, hot springs, and emerald-colored thermal pools, in sharp contrast with the frozen landscape. Bison and elk are drawn to the warmth of the steam.
Almost half the size of Massachusetts, with elevations ranging from 5,130 to 11,358 feet, Yellowstone is predictably snow-covered December through March, and only 55 miles of its 300-mile road system are plowed. The park lies mostly in Wyoming, but includes a sliver of Idaho and some thin slices of Montana.
Yellowstone was the world's first national park in 1872, but winter tourists in any number began arriving only in the 1950s, day-tripping from West Yellowstone, Mont., aboard "Bombardiers," tank-like snowcoaches designed by Joseph-Armand Bombardier for use in rural Quebec. Outnumbered these days by less colorful (though also less noisy and polluting) van-style snowcoaches, Bombardiers were to have been outlawed from Yellowstone by this season. However, saved by their historical status, they remain the park's signature winter transport.
Bombardier also invented one of the world's first snowmobiles. Popular in Yellowstone since the 1960s, snowmobiles transported half of the park's 120,000 visitors last winter. One day during February vacation, some 1,200 snowmobilers filed in through the park's popular West Entrance.
This year, thanks to a ruling in December, fewer than 500 snowmobiles are permitted per day through all four park entrances, and these must be escorted by commercial guides. Visitors are encouraged, instead, to take a snowcoach. The ruling also enforces a 2001 ban on all snowmobiles in the park, beginning next winter.
Yellowstone Park tour guides are a rare, not-to-be-missed breed. Among them is consummate historian and naturalist Leslie Quinn, a native of Orleans.
Our group boarded Quinn's snowcoach, a Chevrolet van mounted on snow treads, at the Mammoth Hot Springs Hotel. Sited near the park's North Entrance and accessible by car and by shuttle from the airport in Bozeman, Mont., this spacious, comfortable inn is a composite of rooms dating from 1911 and 1936, featuring an Art Deco-style lobby and grand Map Room lounge/library. It is sited beside the scattering of 1890s stone buildings that are the park headquarters.
The day's route, with side trips to the Washburn Hot Springs Overlook, the South Rim Drive along the Yellowstone Park Grand Canyon (not the more famous Grand Canyon in Arizona), and then along Yellowstone Lake, covered about 100 miles. Elk and buffalo periodically emerged from the soft veil of snow. In the Hayden Valley along the Yellowstone River, bison blocked our way.
Initially, the park's human visitors in winter were poachers, Quinn said. Traveling on long, heavy, wooden skis, hunters glided up to the animals that couldn't run in the deep snow. Thousands were shot and butchered on the spot. Eventually, the US Cavalry ended the slaughter. The current bison herd numbers around 3,000, Quinn said, compared with 25,000 around the turn of the 20th century.
The buffaloes' presence was soon explained as the river's icy surface gave way to open water and we spotted trumpeter swans and several small ducks. Later, some members of our group saw a gray wolf. Nearly extinct in 1922, gray wolves were reintroduced into the park in the mid-1990s.
After the tour, I rejoiced in the welcome warmth of the blazing hearth in the two-story, open- timbered lobby in the Old Faithful Snow Lodge. Not to be confused with the grand, multigabled vintage 1904 Old Faithful Inn, this is a new, superbly designed and detailed lodge geared for winter that sits within sight of both the famous summer inn and its namesake geyser. There are 230 winter rooms in the park's two full-service hotels, compared with more than 2,000 units in summer.
Good cross-country ski equipment is available at Snow Lodge, and snowcoaches shuttle skiers to several trailheads. One morning, Quinn deposited a few of us at the Spring Creek Trail, not far from the Continental Divide. All night it had snowed -- feathery powder snow. Aside from an initial uphill, the ungroomed trail ran slightly downhill along the length of a narrow canyon, eventually joining a wider trail along the Firehole River to the Lone Star Geyser. It was a beautiful, tranquil day in Yellowstone Park.
As we reentered the Old Faithful Snow Lodge, guests were rushing out as though there were a fire. The world's biggest geyser was due to gush at 4:40 p.m. We found a good vantage point, but when Old Faithful blew, my camera was focused elsewhere, on a coyote slinking along beside the bison.
Next morning, we were off again, this time in a bright yellow 1970s Bombardier, bound for West Yellowstone, self-proclaimed "snowmobile capital of the country." We sampled a 24-mile loop, billed as the country's First National Snowmobile Recreational Trail, a gentle riverside ride and then a scramble up Two Top, a mountain with a summit just broad enough to support a fleet of snow machines. The view included the Grand Tetons and Rockies.
In Switzerland, a cog railway would have gained this view, but this was Montana, a fact underscored by every hour spent in West Yellowstone (population 1,020). The two-block downtown begins at the 1908 Union Pacific Railroad station and shops cater to snowmobilers, cross-country skiers, and fly fishermen. At Eino's Tavern north of town, patrons broil their own (Montana) beef, and the choice of local brews is broad. West Yellowstone also is known for its impressive system of well-groomed cross-country trails, leading from town out into the national forest. Guided snowshoe hikes are offered regularly.
Despite the cross-boundary straddle of this park, one feels in no particular state or nation. This is simply one of the world's most spectacular landscapes, especially in winter.
Christina Tree of Cambridge is coauthor of "Massachusetts, An Explorer's Guide."