In June 1988 summer tourists flooded into Yellowstone National Park eager to see the Old Faithful geyser, fish the lakes and streams, and watch the grazing herds of elk and bison.

The weather was unusually warm and dry that year, and several small fires started by lightning were already burning in the park.

By July the worst drought in park history had taken hold. Meadows turned brown under the blazing sun and forests were parched for lack of moisture.

Without warning the warm breezes grew into strong winds, then into gales gusting up to eighty miles per hour, whipping small fires into a giant conflagration. Walls of flame two hundred feet high devoured the dry timber, and smoke rose in mushroom clouds to forty thousand feet.

The fires burned throughout the summer, finally closing in on Old Faithful at the end...