This story was originally published by Slate and is reproduced here as part of the Climate Desk collaboration.

The town of West Yellowstone should have spent last week focusing on the influx of tourists in town to celebrate the 100th anniversary of the founding of the National Park Service, the culminating huzzah of the much-publicized park centennial that’s been taking place all year.

Instead, they’ve been worrying about fire.

The Maple Fire started on Aug. 8 and has burned 33,000 acres inside the park, which makes it the biggest fire inside the park boundary since the massive fires of 1988. Two days before the 100th birthday celebration (last Thursday), smoke hung low in the streets, the sunrise was red and apocalyptic, and the entire town smelled like a campfire. As the fire continued to grow, air quality was downgraded from “unhealthy for sensitive groups” to just plain “unhealthy,” and nervous tourists could be seen sporting surgical masks. The guy who gave me my motel key complained about his lungs. “You know they’re not even fighting this fire?” he said, incensed. “Not even trying to put it out.” Several bus tours had already been canceled due to concerns about the smoke. On Tuesday, the park service announced that it would close the southern entrance to the park due to another fire burning in the Grand Tetons. “There has definitely been an economic impact, though we don’t know the extent of it yet,” West Yellowstone’s town manager, Daniel Sobolsky, said. “We have such a short season here that every day makes a difference.”