A 26-year-old California woman has died after falling some 600 feet from the landmark Half Dome rock formation in Yosemite, a park spokeswoman said on Monday.

Hayley LaFlamme was climbing down the granite monolith with the aid of fixed-line cables anchored into the rock on Sunday when she plunged to her death, Yosemite National Park spokeswoman Kari Cobb said.

"She fell off the Half Dome cables and fell approximately 600 feet," Cobb told Reuters. "We received 911 calls reporting that she had fallen and our rangers were flown to the sub dome of Half Dome and pronounced her deceased when they arrived."

Half Dome, which rises more than 4,700 feet above the Yosemite Valley floor, is one of the park's signature rock formations and a popular destination for both hikers and rock climbers.

A death investigation was underway to determine the cause of the accident, but Cobb said LaFlamme fell while descending Half Dome using cables installed to help climbers ascend to the summit without the use of rock climbing equipment.

She had apparently hiked to the summit with three other people.

"She was about halfway down the cables," Cobb said. "There had been thunderstorms and lightning rain, and so the granite was very wet and very slippery."

LaFlamme, who was visiting Yosemite from her home in San Ramon, east of San Francisco, was the 14th person to die there this year, Cobb said, marking a especially treacherous year for the popular national park.

Last month, three people who had been playing at the top of the 317-foot Vernal Falls waterfall plunged over the edge and were presumed dead, although their bodies have not been recovered.

Two other people drowned at the Hetch Hetchy Reservoir in June and a hiker died after slipping into the Merced River from the Mist Trail, which climbs alongside Vernal Falls.