Tourists bundled in jackets against the brisk, chilling wind sit on wooden benches awaiting the next eruption of Old Faithful, the nation's most popular geyser.
As always, the ever-smoking geyser does not disappoint. First there is a little puff of water, then another, then nothing for a few more minutes. The crowd is expectantly quiet. Now a few more low squirts, then higher ones.
And now the full works, an awesome display of nature.
But on Sept. 9 this year, another awesome display of nature forced tourists to back away rather quickly from Old Faithful.
It was a creature that once roamed freely through much of the Old West, but whose existence is now threatened by man - a creature that has inspired legends, fear, and respect, and whose very name gives pause: ursus arctos horribilis, best known as the grizzly bear.
The grizzly walked calmly by Old Faithful, even timing the visit to coincide with an eruption. Perhaps it was curious about the fuss day after day over a geyser. More likely it was attracted by food smells.
For years, visitors to Yellowstone used to watch black bears come out on the roads and wait for handouts from tourists anxious to snap pictures of a wild creature so close. But even then, grizzlies were a much rarer sight. Today bear feeding is prohibited, and sighting a grizzly is rare.
But some are still out there, although only a few compared to the 100,000 or so that once lived in the Western states. There may be no more than 700 to 900 left in the lower 48 states - squeezed into about 1 percent of their historic range, according to Christopher Servheen, a biologist with the United States Fish and Wildlife Service.
Grizzlies are federally designated as a ''threatened'' species, only one step away from ''endangered.''
The government would like to keep the grizzly population at least at current levels. Some federal officials, including Mr. Servheen, say they are ''cautiously optimistic'' that their efforts are beginning to turn around the long decline.
Still, they cannot be sure. Counting grizzlies is not easy. They don't just line up. Other experts on grizzlies believe their numbers continue to decline.
The leading cause of grizzly deaths continues to be man. About 135 grizzlies have been killed by man since 1980, according to federal estimates. And hunters, whether legally (Montana still has a grizzly hunting season) or illegally, are not the only ones responsible.
About half the grizzly bear deaths in recent years have been accidental deaths caused by federal officials, says Stephen Mealey, supervisor of the Shoshone National Forest in Wyoming.
Officials kill the bears after they injure someone or become ''addicted'' to human garbage and return one too many times. When there is room in zoos for the grizzlies, they are sent there. But often there is no space.
One grizzly was killed when a sling on a helicopter being used to relocate the bear broke, according to park officials. Others die accidently due to tranquilizing drugs given them during the relocation, Mr. Mealey says.
At the same time, development pressures on the remaining habitat of the grizzlies is increasing.
All but about one percent of their habitat is on federally owned land. National forests account for about two-thirds of that. But these forest lands are seeing continuing oil and gas exploration, timber cutting, road building and recreational use. Bear experts say the activities push grizzlies back to ever more confined areas.
''We are still losing habitat'' and grizzlies, says Charles Jonkel, a University of Montana research scientist, who is director of the Border Grizzly Project, a private US and Canadian effort.
On private land in Montana there has been a steady expansion of subdivision homes on land that until now was territory frequented by grizzlies.
This year shortages of huckleberries and choke cherries, favorite foods of the grizzlies at higher elevations, caused the bears to come down to lower levels, looking for food. Bears were ''popping up all over,'' Professor Jonkel says.
And because the grizzlies are going into their dens now with less winter fat than usual, he says, they are likely to again be roaming beyond their usual territory in search of food. But Servheen says some researchers have found no weight loss on bears they have examined. Apparently the bears switched to other food sources, he says.
Switching to other food sources, Jonkel says, has resulted in a higher-than-usual number of conflicts between the bears and people. The numbers of such conflicts are small, but the publicity around them often is not. ''Vicious Grizzly Brutally Devours Precious Sheep,'' said one Montana headline.
This summer a woman was killed by a grizzly in Yellowstone. A man was stalked and killed last year by a grizzly near the park. But such deaths are rare.
Since 1900 grizzlies have killed 14 people in the lower 48 states, says Servheen, grizzly bear recovery coordinator for the federal government. The two who were recently killed apparently followed safety guidelines for camping, park spokesmen say.
''You'll get a real aggressive one sometimes,'' he says, but the risk of such an encounter is ''very small.'' Usually the bears retreat when they hear people coming. When surprised, cornered, or when a mother is with cubs, however, there is danger, bear experts say.
Bear-human conflicts are extemely rare. Some 2.5 million people visit Yellowstone a year. About 17,000 registered last year for back-country, day, or overnight trips, according to park figures. Less than a dozen people have been injured in the park by grizzly or black bears since 1980, says one park official.
Should the main grizzly habitat in Yellowstone be closed to campers and hikers, as it was temporarily after the woman was attacked? That debate continues. But as bear experts point out, grizzlies don't read signs and are likely to roam beyond restricted areas.
There are currently about 200 grizzlies in Yellowstone, Servheen says. Only 1 percent of the park, or about 30 square miles, has been closed full-time to visitors because of grizzlies. In that area, the number of grizzly sightings by tourists along an area road has increased as the bears have felt freer to graze on open fields nearby. Another 16 percent of the park is closed from time to time because of grizzlies.
Federal steps under way to protect grizzlies and the public include:
* Increased public education efforts on safety and the plight of the vanishing bears. Officials say campers are being increasingly prudent and cooperative.
* Increased presence of rangers and state game wardens in grizzly territory to try to reduce poaching.
* Research to better understand the habits of the bears and how to protect them.
* A push to get the few remaining garbage sources on public lands guarded in bearproof containers to reduce the attraction to bears.
* Stiffer penalties against poachers. Prosecutions have been slow, some bear experts complain.
* Use of devices in national forests to help elk hunters reduce possible conflicts with grizzlies. These devices include steel, bearproof boxes and raised platforms, or electric fences for hunting parties that store food and horse feed. Hunters on federal lands are no longer permitted to use horse carcasses as bait for black bear kills, since grizzlies were sometimes showing up instead and being shot, says Mealey of the US Forest Service.
But not everyone is happy about efforts to save grizzlies.
''We're getting frustrated,'' says Bob Gilbert, secretary-treasurer of the Montana Wool Growers Association. ''We don't feel our sheep should be grizzly food,'' he says.
A small number of sheepherders have been granted permission to graze sheep on federal lands that are in grizzly territory. Some have had sheep attacked by the bears. While some advocates for the grizzly recommend an end to such grazing in those areas, Mr. Gilbert says, ''food production and wool production ought to come first.''
And while most experts say public sentiment had turned in favor of the grizzlies in recent years, some local reactions against them may be growing, partially as the result of the recent bear-human conflicts.
Montana last year made the grizzly the state animal. But Paul Schullery, a former National Park Service historian and ranger and author of The Bears of Yellowstone, says many people are ''out of sympathy with the grizzly. They resent the restrictions (by state and federal government on behalf of the grizzly) for an animal they never see, in a perpetually depressed area. They want more business.''
''You're starting to get more of a backlash'' of people unhappy with the bears, says John Drake of the US Forest Service. ''Not only the bears need to survive, but the humans,'' he says.
Jonkel says the US Forest Service is building too many roads for timber cutting and oil and gas exploration in grizzly territory. But Mr. Drake, a former supervisor of the Gallatin National Forest in Montana, grizzly habitat, says the roads and exploration can be done in ways that don't interfere with grizzlies. Certain restrictions are in effect, he says.
Keith Aune, a biologist with the Montana Department of Fish, Wildlife and Parks, is now studying grizzlies. He says the key to such activities is their cumulative effect on the bears.
Suddenly a road is put in, he says, then come greater timber harvesting, more vehicles, and snowmobiles. ''You add all of them together,'' he says, and the effect is harmful to the bears. ''They retreat.''
Thomas McNamee, whose book, The Grizzly Bear, has just been published by Alfred A. Knopf of New York, says a ''radical'' shift in policy by the US Forest Service is needed to insure survival of the bears. Instead of using all national forests as multiuse lands, the portions in grizzly territory should be restricted to uses not harmful to the bears, he suggests.
Preserving the bear means ''there are sacrifices to be made,'' says Jay Copeland of the Audubon Society, who has been working hard to promote the grizzly's cause.
But, he adds, ''whether the grizzlies survive in the Yellowstone (area) well into the 21st century is an open question.