BIG SUR — The engineers and laborers who constructed California State Route 1 from Carmel to San Luis Obispo County beginning in the 1920s knew the road was fraught with peril. But they did it anyway. Coastal communities in the area needed better access to health care and other resources.

Engineers and prisoners alike risked life and limb as they built the two-lane highway into the majestic coastal cliffs of the Santa Lucia mountains. The 18-year project eventually connected San Luis Obispo to Carmel via the seaside, where the geology makes the road inherently susceptible to landslides. The 1937 grand opening even included a symbolic blasting of a boulder, which the governor cleared from the road with a bulldozer. It was the first of many to come.

Now, incessant storms are causing landslide trouble on Highway 1. Again.

Multiple problems

A 45-mile section of Highway 1 extending from Deetjen’s Big Sur Inn in Monterey County to Ragged Point in San Obispo County is currently closed due to landslides, with no estimate on when it will reopen. And residents, businesses and Caltrans crews along the Big Sur coast are bracing for more geological activity as winter storms continue rolling in.

Closures like this along the Big Sur coast are not uncommon. Residents and businesses aren’t surprised when they are temporarily cut off from the world. Caltrans engineers know they must move mountains off the road. Repeatedly.

But nobody gives up on California’s crown jewel highway, which is recognized by the U.S. Department of Transportation as a National Scenic Byway. Laborers, who seem to be working continuously to repair damage and rebuild sections after landslides, are lauded as heroes, and locals host celebrations for reopenings.

‘Challenges and rewards’

“A ribbon of highway on the edge of the continent presents challenges — and rewards,” said Kevin Drabinski, the Caltrans District 5 public information officer.

“We make these closures for the safety of the traveling public. It’s an international travel destination, and, just as important, it’s home to communities and businesses. So we try and do the best we can to keep it open,” he said.

Landslides come with the geology of the area. “It’s old ocean floor stuff that makes up a lot of the California coast that’s been accreted or pushed up on the continent, so it’s been faulted and folded and distorted and weakened,” said Gary Griggs, a professor of Earth Sciences at UC Santa Cruz.

Landslides on Highway 1 usually happen during storms, when water hits soil, making the soil heavy, lubricated and more fluid. Gravity sends chunks of mobilized mountainside plunging from steep, sweeping cliffsides into the crashing waves below — or onto the highway.

Caltrans prepares for winter storms in the fall. Crews inspect and clean out culverts, which Drabinski describes as the “unsung heroes of Highway 1.” Some workers even rappel from the cliffs with picks and other tools in hand to dislodge loose rocks. Worker safety is always a priority.

The goal is to make the cliffs as stable as possible going into the winter. “We put special focus on areas that are downslope of the Dolan fire burn scar,” said Drabinski. Previously burned areas are especially prone to slides when the rains start.

The precarious road has been closed due to landslides dozens of times since it first opened in 1937. The road closed 55 times between 1937 and 2001, according to a 2001 report.

The worst event in that period was a 963-foot-high landslide in 1983 near Julia Pfeiffer Burns State Park. The New York Times reported that it took 13 months, 30 bulldozers, 7,700 pounds of explosives, and $7.8 million to clear it, and one bulldozer operator lost his life in the process. When it reopened, residents threw a party with bands, balloons and a 52-foot-long carrot cake, according to the New York Times.

More recent winters have produced some of the worst — and most costly — landslides in the road’s history. Each time, Caltrans has been prepared and quick to respond.

In February 2017 a landslide displaced a damaged column of the Pfeiffer Canyon Bridge. Crews demolished and completely replaced the bridge with a new $21.7 million bridge designed to reduce its susceptibility to landslides. The new bridge was completed in October 2017 after an effort to design and construct a new bridge quickly that Jim Shivers, a Caltrans spokesperson, described in a 2017 article as ”remarkable.”

But the road remained closed to the south — in May that same year, a landslide had buried the highway near Mud Creek, just north of the Big Sur Lookout. The massive event, described in the national news by Executive Director of the Big Sur Chamber of Commerce Stan Russell, as “the mother of all landslides,” buried a quarter-mile section of the highway 40 feet deep. The road reopened 14 months — and $54 million — later.

In January 2021, the road itself collapsed into the sea leaving a steep and terrifying void where the mountainside used to be. But Caltrans took advantage of subsequent dry weather and restored the road faster than anticipated. It reopened in April 2021, nearly two months ahead of schedule and only three months after the initial event.

The repeated cycle of damage and repair seems tedious, but there aren’t many other options for a coastal highway built into the mountainside.

“I think it’s always going to be this Band-Aid approach,” said Griggs. “We fix it up and wait for the next one, but it’s a place where that’s the only choice.”

“We do put a lot of resources into maintaining Highway 1 on the Big Sur coast,” said Drabinski. “It’s prompted out of service to the residents and businesses of the Big Sur community and to the travelers who return there because of its natural wonder.”

Drabinski does not know how long the current closure will last. Caltrans hasn’t had time to assess the full extent of damages yet — the continuous storms are forcing them to stay in response mode. “We are just responding to incidents, and those responses are complicated,” he said.

Normally response crews can approach Paul’s Slide, one of the current trouble spots, from the south. “When the highway is open, we just shoot up from Cambria, go right up the road past Ragged Point and deliver the goods,” he said. But with the southern closure, everything has to detour and enter from the north.

Drabinski said it’s “certainly likely” that conditions will worsen if the rains continue.

Caltrans said in the press release that they “will continue to take advantage of any break in inclement weather to assess road conditions and provide access as long as the conditions are favorable for public travel.”

When Highway 1 does open again, “the best way to view the scenic wonders of the Monterey coast is to park one’s car frequently and to enjoy the views at leisure,” according to a 1937 article in the Monterey Peninsula Herald. “Fortunately the great slides that have taken place during construction have resulted in scores of wide parking spaces, nearly all of them at points where the vistas are the most remarkable.”