The summer opening of a new $14.2 million public park on the San Mateo County coast along a spectacular stretch of sandy beach has been delayed by a year.

Tunitas Creek Beach, located 8 miles south of Half Moon Bay, will open in the summer of 2026 instead, as two large landslides that developed this spring on the property must be repaired, San Mateo County Parks Director Nicholas Calderon said Thursday.

The 58-acre property, once owned by singer Chris Isaak, has a mile-long sandy beach and picturesque cliffs more than 100 feet tall on its northern edge.

Construction began in late 2023 to install restrooms, a parking lot with 60 spaces along Highway 1, a ranger station, a small amphitheater for ranger talks, and wide paths that will enable access for those with disabilities.

Now, two major landslides have undercut a key road to the beach.

“We looked at all the options and came to the conclusion that because the slides are jeopardizing the main access route to the beach, which is the only vehicular access for first responders to access the beach, we have to repair them before we can open the property publicly,” Calderon said.

The county hired geologists to take core samples and other measurements. The county’s public works department is designing a project to repair and stabilize the two large slides. Finalizing them, securing funding for the still-unknown repair costs, and obtaining permits from the California Coastal Commission and other agencies will take until next year, he said.

“People are so invested in the project,” Calderon said. “I think this is the most majestic property on the San Mateo County coast.”

The beach and hillsides around it have a long and colorful history.

Spanish explorer Gaspar de Portola and his men camped along Tunitas Creek in 1769 during their expedition from Baja California to San Francisco Bay. The property was in private ownership for generations, its soaring cliffs and sand dunes hidden from motorists zooming along Highway 1 between Santa Cruz and Half Moon Bay.

A company known as Todd Gelfand Trust, linked to Isaak, purchased the bluff-top land there, a modest 1950s-style house and most of the sand on the beach for $3.1 million in 1998.

Isaak, 68, a Stockton native who had hits in the 1990s with songs such as “Wicked Game,” was never seen at the property, locals say. The singer has declined interview requests to discuss the land purchase.

Starting about 15 years ago, the beach became the site of wild, sometimes dangerous parties. Hundreds of people with stereo systems, disco balls, tents, kegs and mattresses left huge amounts of trash, set off fireworks and used Tunitas Creek Beach as a bathroom during all-night raves. In 2016, a San Jose man drowned there.

Isaak’s trust sold the property to a Palo Alto environmental group, the Peninsula Open Space Trust, for $5 million in 2017, which in turn sold it for $3.2 million to San Mateo County in 2020.

The late county supervisor Don Horsley led efforts for the county to buy the beach, build amenities there and open the first major coastal beach added to the county parks system since Fitzgerald Marine Reserve in Moss Beach in 1969. After Horsley, who was also the former county sheriff, died in 2023, county leaders named the new beach park after him.

Longtime supporters of the project on Thursday described the latest delay as unfortunate.

“We were so disappointed to hear about the landslide and subsequent delay of the opening,” said Gordon Clark, president of the Peninsula Open Space Trust. “That said, we understand the public safety priorities out there. This has been a large and audacious project, and we are here to see it through to completion despite this delay.”

The project has faced other delays. A few weeks after the county purchased the land, the COVID-19 pandemic hit, shutting down many projects. Supply chain issues after that, followed by three wet winters in a row, also slowed efforts.

In June 2023, the county awarded an $11.6 million contract to Gordon Ball Inc. of Alamo to build parking, trails, a ranger station, restrooms, interpretive signs and other amenities at Tunitas Creek Beach.

After construction began, changes and other unexpected costs increased the price to $12.7 million. Last month, the County Board of Supervisors approved spending another $1.5 million to cover costs for additional soils, more aggregate rock, burying utilities, traffic control on Highway 1 required by Caltrans, and other expenses, bringing the total to $14.2 million.

Nearly all the work is finished now, except fixing the landslides, which Calderon said were likely made worse by three rainy winters in a row.

“We are so eager and ready to open this to the public,” Calderon said. “But we need to do it in the safest way possible.”