How to explore reopened underground California wonder

LOS ANGELES — The stalactites and stalagmites of Sequoia National Park’s Crystal Cave, a sprawling subterranean wonder that’s been closed for four years, will be accessible again this summer.

But to get in during the open season of May 23 through Sept. 7, you’ll need tickets, which are available now.

Visitors will walk through the cave on 50-minute guided group tours, inspecting mineral formations and hearing about the cave’s history and rare geology. Rangers describe the trail — a steep half-mile to reach the cave, then a half-mile loop inside — as “strenuous,” featuring possible encounters with poison oak, bees, rattlesnakes and falling rocks. It’s not suitable for young children or anyone with claustrophobia, rangers say, and the stairs are roughly as tall as a 20-story building.

The cave is one of about 275 known caves in Sequoia and neighboring Kings Canyon National Park. The park’s only publicly accessible cave, it has been open to visitors since the 1940s, making it one of the most visited subterranean landmarks in California.

Savannah Boiano, executive director of the Sequoia Parks Conservancy, said many trees died near the cave in the drought of the 2010s, then ignited in the 2021 KNP Complex Fire, forcing the cave’s closure. Next came winter storms in 2023, further damaging the 6 mile road to the cave. To prep for reopening, Boiano said, crews removed hazardous dead trees, repaired roads and replaced the cave’s solar-powered electrical system.

“It really has been the epicenter of some natural disasters,” Boiano said.

Crystal Cave includes more than 3 miles of surveyed passageways, carved by water over roughly a million years. Its temperature is a steady 50 degrees. Its walls are marble — not the granite that dominates the Sierra Nevada range — and an underground stream runs alongside much of the cave trail. The last and largest “room” is known as Marble Hall.

The Sequoia Parks Conservancy is handling the reservations for tours ($21.20 for adults, $11 for children under 10; pets forbidden), which are offered from 9 a.m. to 3 p.m. In May, the tours are offered Friday through Monday, closed Tuesday through Thursday. From June through Sept. 7, tours are daily. Photography is allowed — but flashes, tripods, monopods and selfie sticks are banned. If weather forces a cave closure, refunds are offered.

Tickets will not be sold at the cave, the conservancy said. Park rangers advise visitors to buy cave tour tickets two months ahead, noting that historically, tours have sold out in July and August.