It was terrifying, but there were only minor injuries.
The slide hit the Curry Village camp site, crushing cabins, tents and trees; the volume of rocks would fill about 180 dump trucks.
Fall is rock slide season in Yosemite, especially after rain.
"I thought I heard thunder, but it kept rumbling and rumbling," camper Jeffrey Kloska said. Kloska was asleep in his Curry Village tent cabin when he heard the noise and ran.
"You saw the smoke and the dust come down; it was like 9/11, and the grit was in your eyes and grinding in your teeth," he said.
When the dust settled, the pile of heavy rocks and debris had crushed five tent cabins and two other structures.
"There was a release point in an area called Staircase Falls, which is just behind the Curry Village area," Yosemite Park ranger Vicki Mates said. "From preliminary estimates, we believe that around 1,800 cubic yards of material fell."
Three park visitors suffered minor injuries, including an asthma attack by someone running from the debris.
Vacationing nurse Linda Jameson treated one boy who had lacerations to his head.
"It was a clean cut, I think he probably got hit by granite shrapnel," Jameson said.
The structures that were crushed were all unoccupied, partly because they were in the same area as a smaller slide Tuesday.
Park officials and geologists met Wednesday afternoon to decide what to do about the area near the slide. About one-third of the campers were let back into eastern end of Curry Village, the area furthest from the slide area. They will meet again Thursday to decide if the rest of the area will reopen.