Evidence of forest fires was nearly everywhere as we traveled throughout the park.
I am not sure how many of the images below show the result of the historic Yellowstone fires of 1988. I think a few of the landscapes must be of more recent fires, as only grass has grown back.
The fires of 1988 started as many small fires whose flames spread out of control due to unusually hot and dry weather. Eventually the fires merged into one massive fire which burned for many months.
A total of 36% of the park was effected by the fires (over 790,000 acres). At the peak of the firefighting effort over 9,000 firefighters were working in the park and they were supported by over 4,000 military personnel.