If you haven't been to Yellowstone since the wildfires marched through the park in the summer of 1988 (and record numbers of tourists have been counted in the aftermath), be prepared for a bit of shock. To rework an old saying, "The name's familiar, but the face" . . . is not quite the same.

Mountains, streams, wildlife and geyers were affected very little, of course. But whole tracts of forest were charred by the rampaging flames. Lines of toothpick sentinels atop once-tree-topped ridges catch your eye. At this time of year, still-black trunks poke through the snow; some reflect somberly in quiet pools. Evidence of the pine-beetle attacks that helped pave the way for the fires, abetting the drought, is also still readily visible.If you're not expecting the same old Yellowstone, the park's changes can be intriguing. The National Park Service is certainly taking the brighter point of view.

"Yellowstone is still the magnificent place it always has been; fires are a part of the life processes here, and the park's vegetation is regenerating as it has countless times before," Superintendent Robert Barbee writes.

"I think it looks great," says Park Ranger Caroline Evans. "I was here prior to the fires, and in '59 during the earthquake, so I've seen Yellowstone over the years. And it certainly is a changed Yellowstone, but I would not say it's any worse for the wear. In fact, I'd say it was improved.

"Last year's wildflowers, the meadows and the greenup, were the best I've ever seen. The variety of plantlife that burgeoned after the fire was just outstanding.

"The forests themselves also have lots of little green things coming up," Evans says. "The lodgepole pine needs fire to germinate. More than 15 percent of the cones specifically will not open unless they get a temperature of 115 degree Fahrenheit . . . If you're from the Southwest, you'd get that; but it's very rare in Yellowstone. The only time that would happen is if you had cones locked in a car on a hot day - or in a forest fire."

But, she admits, "It's going to be a long time before we have a thick forest."

About 36 percent of the park's 2.2 million acres were affected by the fires. That doesn't mean all of those parcels were burned; flames jumped. In some places most of the trees were ablaze, in others only a few were singed.

Vegetation quickly reoccupied open areas that were burned, and in many stands, Evans says, tree seedlings are growing as thick as grass. "They'll thin themselves out as time goes by."

A questionnaire study conducted in July 1989 by the University of Idaho at Moscow bears out the Park Service contention that the fires initially did little to deter - or even lure - tourists.

Of the 1,070 questionnaires distributed, 856 were returned. The researchers found that 64 percent of the respondents said the fires were not a reason for their visit, while 7 percent indicated the fires were their primary reason for coming. Almost half (48 percent) said they felt the fires were beneficial to the park's natural systems; 28 percent said they were not and 24 percent didn't know.

Almost equal numbers of comments indicated that the park appeared worse than expected - or better than expected.