Highway 18 in San Bernardino Mountains being inspected for avalanche threat

A Caltrans avalanche crew plans to inspect a 7-mile stretch of Highway 18 in the San Bernardino Mountains on Wednesday, March 8, out of concern that the snowpack could give way above the roadway.

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 San Bernardino County.

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.

The team is arriving from the Caltrans district that serves Sacramento, El Dorado, Yolo and Placer counties, among others. The local district, which serves the Inland Empire, does not have an avalanche crew, Dionne said.

There are no homes or businesses in the area, but motorists and 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 record-breaking snowfall.

Mt. Baldy Resort, in the San Gabriel Mountains, reported several avalanches on March 1. Mt. Baldy, at more than 10,000 feet, is the highest peak in that mountain range. Most avalanches happen on slopes that are steeper than 30 degrees. That means they are not expected to happen 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, the crew 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.

Source: Orange County Register