The Christmas weekend storm brought snow and bad manners to Southern California mountains.

With more snow expected this weekend, authorities are urging people to abide by laws when traveling in the San Bernardino, San Jacinto and San Gabriel mountains.

Winter visitors took home loads of snowy “White Christmas” memories over the past few days. But they left behind monstrous amounts of litter and traffic headaches from Wrightwood, Running Springs and Big Bear south to Idyllwild, said state and local officials at a press conference Wednesday, Dec. 28, in San Bernardino.

“Please don’t trash California,” John Bulinski, California Department of Transportation District 8 director, said at a bilingual rooftop press conference at the Rosa Parks Memorial Building garage.

Officials offered tips to teach snow newbies better mountain manners.

California Highway Patrol Officer Juan Quintero, speaking in English and later Spanish, warned mountain visitors to avoid citations by carrying tire chains in their vehicles, not blocking roadways to install chains or play in snow, and not leaving plastic sleds or garbage behind.

“It’s illegal to litter,” said Quintero, based in Lake Arrowhead. “Make sure you don’t trash the mountains when you come up here.”

Traffic problems began Friday night and continued into Wednesday. The worst congestion has been on highways 330, 18, 38 and 138. Highways 189 and 173 also have seen problems, Caltrans spokeswoman Terri Kasinga said.

More than 100 vehicles were stuck on Highway 38 in the San Bernardino mountains for more than four hours on Christmas Eve because drivers didn’t have chains, she said.

Others were blocked on Highway 2 in the San Gabriel Mountains after people parked on the highway to rent snowboards from a nearby shop.

Some visitors actually played in the snow on highways in front of traffic, Kasinga added.

Blocking mountain roadways is illegal and creates driving hazards. That also prevents snow plows from clearing ice and snow off highways and emergency vehicles from responding to crimes, medical emergencies, fires or rescues.

Resident volunteers and businesses in mountain communities and inmate crews clean tons of trash left in the mountains by visitors each winter. Some who are tired of what’s become a big annual headache vented their frustration against “flatlanders” on social media this week.

Litter harms animals, people and the environment – and attracts more litter, damaging a community’s image, Bulinski said.

Garbage – most commonly food and drink containers, plastic sleds, cigarette butts and used diapers – are eyesores whose toxic materials create health and fire risks, said Liz Brown of CalFire.

San Bernardino County Supervisor Janice Rutherford, whose Second District includes San Gabriel and Rim of the World mountain communities, asked visitors not to discard garbage or snow toys in the national forests, roadsides or other people’s yards.

“You wouldn’t want anybody to come to your neighborhood and leave dirty diapers or fast food trash in your yard,” she said. “We ask that you have the same respect for the residents of our mountains.”

Contact the writer: 951-368-9444 or shurt@scng.com