Yosemite National Park will permanently close about a third of the lodgings at popular Curry Village after repeated and sometimes deadly rockslides during the past dozen years.
The announcement Friday came about six weeks after a slide destroyed one cabin and damaged more than a dozen others, prompting an evacuation involving about 1,000 visitors.
The National Park Service and the U.S. Geological Survey studied the granite cliff of Glacier Point above Curry Village, officials said. Officials decided to tear down 233 lodging units within the rock debris field at the bottom of the cliff.
"It's to protect visitors," said Yosemite spokesman Scott Gediman. "There has been an increase in rockfall over the last 10 years or so." Two people have died in rockslides at Curry Village since 1996, and several have been injured. The park service closed 27 cabins in 2003 after a rockslide.
Scientists said rockfalls have been occurring more often during the past decade all around Yosemite Valley, a seven-square-mile area ringed with glacially sculpted cliffs. They had no explanation other than the variability of nature.
Rockfalls have occurred sporadically over many tens of thousands of years in the valley, scientists said, and they are impossible to predict with precision.
"It might go another 50 years without a big incident," said Edwin Harp, a U.S. Geological Survey scientist who helped assess the Curry Village danger last month.
But rockfall is a big issue in Yosemite, where more than 3 million people visit annually. An estimated 70% of the visitors pass though the valley.
The rockfall last month happened about 7 a.m. on a weekday, reportedly minutes after schoolchildren had departed the area to get breakfast.
Park service officials closed 269 of the 600 lodging units at Curry and began a scientific investigation.
On Friday, they issued a statement: "The NPS can no longer treat each rockfall as an isolated incident. Instead, we must look at the area comprehensively and recognize that geologic processes that have shaped Yosemite Valley since the last glaciers receded will continue to result in rockfall." Officials also reopened 36 cabins, saying they were not in the area at risk.
A 1996 rockslide was more spectacular than the one in October. A 20-year-old Southern California man was killed after more than 100,000 tons of rock broke free from Glacier Point and plunged into the Happy Isles area near Curry Village.
The impact created a blast of wind more than 100 mph, flattening more than 500 trees. The fallen granite was pulverized on impact and raised a plume that hung in the valley like a light-gray fog.
In June 1999, a rockslide killed a 22-year-old Colorado man who was visiting Curry Village.
The village, established in 1899, is one of the busier places in the valley, offering visitors various kinds of cabins, stores and restaurants.