Avalanche inspection planned along 7 miles of snowed-in highway

A Caltrans avalanche crew plans to inspect a 7-mile stretch of Highway 18 in the San Bernardino Mountains today out of concern that the snowpack could give way above the road.

The portion of Highway 18 between Snow Valley Mountain Resort in Running Springs and Big Bear Dam is the only state highway in the San Bernardino Mountains that remains closed. Crews on Tuesday were pushing their way through 10 feet of snow in the eastbound lanes to clear a path for the team, said Eric Dionne, a spokesman for Caltrans District 8 in the Inland Empire.

Snow Valley is closed, the resort website says. The Bear Mountain Resort is open, but only those who live in the mountains are allowed up.

A Caltrans avalanche team in the district that serves Sacramento, El Dorado, Yolo and Placer counties, among others, was asked to review images of the mountainside, said Steve Nelson, a Caltrans spokesman in Marysville. That review had not taken place yet, he said Tuesday afternoon.

Caltrans District 8 does not have an avalanche crew, Dionne said.

There are no homes or businesses in the area, but motorists, the road and guardrails are at risk, Dionne said.

The steep terrain at 7,000 feet makes this portion of the mountains potentially susceptible to avalanches, he said, similar to 9,000-foot Onyx Peak off Highway 38 to the south. Slides onto Highway 38 caused the road to remain closed to all traffic until Monday.

Experts say avalanches can happen on steep slopes that have lots of snow in layers. When the first layer freezes, the second layer can slide when triggered by something such as additional snowfall or wind. The San Bernardino Mountains have experienced recordbreaking snowfall.

Mount Baldy Resort, in the San Gabriel Mountains, reported several avalanches on March 1. At more than 10,000 feet, Mount Baldy is the highest peak in that mountain range. Most avalanches occur on slopes that are steeper than 30 degrees. That means they are not expected to occur at Bear Mountain Resort, said Justin Kanton, a spokesman for the three San Bernardino Mountains properties.

Fourteen people have died in avalanches nationwide during the winter of 2022-2023, according to avalanche.org.

Dionne has worked in the Inland Empire for eight years and can’t recall bringing in an avalanche crew in that time.

If it’s determined that there is avalanche danger, crews can set off controlled, small avalanches that can be cleaned up. One method is to shoot cannons that fire a mixture of oxygen and propane that acts as a concussive blast. Another method is to fire charges that detonate in the snow.

“It’s like they are shooting up a little piece of dynamite,” Dionne said.