A firefighter attempts to stop the fires near Norris Geyser Basin, August 20, 1988, better known as "Black Saturday" In Yellowstone National Park. More than 150,000 acres burned on that one day, and the smoke was so dense in places, it turned daytime into night. Image retrieved from NPS archives and taken by Jeff Henry...[1] of the Yellowstone Digital Slide Files which are all in the public domain [2]

This image or media file contains material based on a work of a National Park Service employee, created as part of that person's official duties. As a work of the U.S. federal government, such work is in the public domain in the United States. See the NPS website and NPS copyright policy for more information.