1996 Yosemite Valley landslide

1996 Yosemite Valley Landslide

Aftermath of the landslide
Date	July 10, 1996 (1996-07-10)
Location	Yosemite Valley, YNP, Mariposa County, CA, United States
Coordinates	37°43′44″N 119°33′40″W / 37.729°N 119.561°W / 37.729; -119.561
Cause	162,000 tons of debris fell at speeds of up to 160 mph[1]
Deaths	1

The 1996 Yosemite Valley landslide occurred on July 10, 1996, near the Happy Isles trailhead in Yosemite Valley, Yosemite National Park, Mariposa County, California. 162,000 tons of rocks and other debris fell to the ground at over 160 miles per hour. Of the 12 campers/hikers involved in the incident, one was killed. The landslide competes with the 1997 Merced River flood and the 2013 Rim wildfire for the designation of the worst natural disaster in Yosemite to date. The earthquake caused by the rock slide was followed almost immediately by a sonic boom. Soon afterward a granite dust mushroom cloud formed over Happy Isles. The immense pressure created at the base of the rock slide blew down giant pine trees as if they were nothing. Afterwards the nearby campground tables and trees were covered with a thick coat of granite dust.