[My2Cents]

What city? I've visited about a dozen national parks, and I don't recall any cities even close to them. I suppose West Yellowtone, Montana, is the closest I've seen.

The 1988 wildfires in Yellowstone burned about half the acreage. Interestingly, they started outside the park. The combination of drought and some 49 small fires started by lightening strikes that merged into major fires, made fighting them virtually impossible. The main heroic fire-fighting efforts were in the attempts to save the Old Faithful Inn, but it was a shift in wind that actually saved the structure. And then it was more the return of rain and an unusually early snowfall in September that finally put the fires out.

[Tolerance Sucks Rocks]

If not a city, then the danger always exists that some public place (such as the Old Faithful Inn) or somebody's home could ultimately be burned down by a "natural" fire that started in a forest in which environmental policies have allowed too much dead wood (firewood, for want of a more accurate word) to accumulate. My point is, the country is simply too settled to allow forests to go wild.