On this day: August 20

Published On: Aug 19 2012 02:46:11 AM CDT   Updated On: Aug 20 2014 01:00:00 AM CDT

Charles Darwin publishes his theory of evolution, the NFL is founded, Lou Gehrig belts his 23rd career grand slam and NASA heads for Mars, all on this day.

OTD August 20 - Yellowstone fires
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National Park Service

1988: Firefighting continues in Yellowstone National Park, with the wildfires burning so much ground and producing such thick black smoke that the day is labeled "Black Saturday." The fires were part of a series of nearly 250 wildfires that burned through the park starting in June. On Sept. 8, 1988, the entire park was closed to all non-emergency personnel for the first time in its history.

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