In the summer of 1988 numerous fires burned 793,000 acres of Yellowstone National Park as well as large tracts of land surrounding the park. Half of the acres burned inside the park resulted from fires that started outside the boundary. Nine of the fires were human-caused, and 42 were started by lightning.
On the worst single day, “Black Saturday” on August 20, 1988, tremendous winds pushed fire across more than 150,000 acres. Throughout August and early September, some park roads and facilities were closed to the public, and residents of nearby towns outside the park feared for their property and their lives. Yellowstone’s fire management policy was the topic of heated debate, from the restaurants of park border towns to the halls of Congress. Following this event, the National Park Service and other federal land management agencies rewrote their policies affecting how they managed fires with less than full suppression strategies.
For more info:
http://www.nps.gov/yell/planyourvisit/upload/firesupplement.pdf
I remember very well watching fire just seem to explode all aroud us on the 20th in Yellowstone. I was in a great position to see a fire start from a downed powerline and just blow up in a matter of a few minutes into a roaring crown fire with one half mile or more spotting. I was able to capture the whole thing on film and somewhere in my collection of slides have them.
What a day!