Southern California’s latest batch of wintery weather has led to San Bernardino County officials declaring a state of emergency.

The emergency proclamation was made Monday evening, after many residents in the county’s mountain communities spent the weekend stranded or trapped at their homes due to several feet of snow.

The proclamation also comes as another storm system prepare to land in California, bringing with it even more snowfall in the upper altitudes.

Board of Supervisors Chair Dawn Rowe, whose district includes many of the impacted communities, called the emergency declaration an “important step” in securing state and federal assistance to clear out the snow from mountain highways, residential streets and other critical repairs and infrastructure work.

“Our team of state and local partners will continue working round-the-clock on a coordinated and comprehensive strategy to bring relief and resources to our residents, while also prioritizing the safety of all,” Rowe said.

On Monday, heavy snow stranded hundreds of motorists on highways that travel through San Bernardino County’s higher elevations. Dozens of elementary school children were also stranded at a science camp in Crestline for nearly a week. The California Highway Patrol was eventually able to escort a fleet of buses to evacuate the stranded students.

By Tuesday, Highway 18 through Lucerne Valley was finally opened, but to Big Bear residents only. Proof of residency is required to get through for food, gas and emergency services if needed, city officials said.

Additionally, Caltrans and CHP officials began escorting residents for “upbound” traffic on the highway at 48 Street in San Bernardino and Highway 330 at Highland Avenue around 5 a.m. Tuesday, depending on where they live.

Residents were escorted from 5 a.m. to 9 a.m. and again between 5 p.m. and 9 p.m.

Proof of residency and chains are required.

“An important note, these escorts are only temporary, if traffic becomes inundated and there are situations causing delays, the escorts will stop. If resident’s come down the mountain, you might not be let back up,” Caltrans officials explained. “Be prepared if this occurs, but it is better to stay home and off the roadways.”

County officials said crews were working around the clock to clear some of the affected roadways and, although progress was being made in residential areas, there was no estimate for when the highways would be cleared.

Heavy equipment is currently being deployed to help remove the snow, but there are limitations into how much can be moved.

Several local law enforcement agencies have had to divert resources to conduct search and rescue for people getting stranded while making non-essential trips.

“Caltrans didn’t have enough people, as well as equipment, to keep up with the storm, so they got backed up,” said Officer Ryan Mohatt of the CHP.

The San Bernardino County Fire Department is currently using “specialized snow vehicles” to reach patients in critical need of medical attention.

Local authorities are urging residents to avoid traveling on these dangerous roads to allow for critical work to be completed. Once the major arterial roadways are cleared, the focus will then turn to the secondary streets.

However, the amount of snow and ice on the roads could be a moot point for some drivers, as gas stations are reportedly running out of many types of fuel. Grocery stores are also running out of food, as shown in footage of bare shelves at Goodwin & Sons Market in Crestline.

In the meantime, residents from the mountain communities who find themselves stuck away from their homes can take advantage of an American Red Cross center at East Valley High School in Redlands at 31000 E. Colton Ave. The shelter will be staffed from 8 a.m. to 7 p.m.

A call center will also be in operation Monday through Friday from 8 a.m. to 7 p.m. That number is 909-387-3911.

The county also has a Frequently Asked Questions section regarding the storm and cleanup efforts on its website.