Rocky Mtn National Park
On July 15, 1982 at 5:30 a.m. Lawn Lake broke through the terminal moraine that had held since the end of the last ice age, thousands of years ago. The release of 29 million gallons of water swept trees and car-sized boulders four miles down to the valley floor. In addition to tons of lighter rocks, gavel and sand creating a 42-acre alluvial fan.