A massive crack opened in a Yosemite National Park cliff, raising the risk of a dangerous rockfall and forcing the indefinite closure of part of a popular trail, park officials said.
Climbers recently reported the crack on the western side of the Royal Arches, near a climbing route known as Super Slide on the Yosemite Valley Loop Trail, according to the National Park Service.
Upon further investigation, officials discovered that the crack had partially detached from a large rock pillar and that the split was growing.
A climbing guide who scaled the rock face on August 6 did not see the crack; By the time of his ascent on August 20, the crack, up to an inch wide and 200 feet long, had already appeared, recreational magazine Outside reported.
“A ranger and a geologist observed it firsthand and could hear it cracking like a frozen lake that wasn't consolidated,” Supervising Ranger Jesse McGahey told Outside. “And there were pieces of rock falling through the crack without touching it. The park's geologist said they had never seen anything like it. He has never been able to observe that in his 15 years in Yosemite.”
As a precaution to reduce the risk of potential rockfalls, the National Park Service closed a quarter-mile of the Yosemite Valley Loop Trail at the Ahwahnee Hotel. There is no timeline for a full reopening of the trail, but hikers can take a detour in the meantime.
All climbing routes from Peruan Flake West to Rhombus Wall are also closed, including the popular Serenity Crack/Sons of Yesterday and Super Slide routes.
Rockfalls are relatively common in Yosemite and increased last year when strong fall storms hit the area. In 2022, Yosemite had a total of 52 documented rockfalls within the park, recent data shows.
The largest rockfall of 2022 occurred in November from the middle height of Middle Brother, part of the Three Brothers granite formation. A rock slab weighing approximately 4,000 tons broke away from the face of Middle Brother and struck a ledge, dislodging more than 440 more tons of rock from two other points at the lower end of the cliff. Some rocks caused damage to Northside Drive.
On December 27, another rockslide east of the park's Arch Rock entrance fragmented into dozens of rocks, struck a vehicle on El Portal Road and killed two people inside.
