LOS ANGELES (CNS) - Snowplows were dispatched to remove numerous rock slides that closed State Route 18 between Big Bear Dam and Snow Valley today, as a magnitude 4.6 earthquake and a possible strong aftershock hit the San Bernardino Mountains resort areas, and were felt from Mexico to Bakersfield.

At least six vehicles were stranded on the road, including an SUV and three motorcyclists, CHP officers said. There were no initial reports of injuries or damaged cars on Route 18.

But 20 miles away, near Forest Falls, a compact car on Route 38 hit a rockslide and tore out its undercarriage, CHP officers said. The Volkswagen Golf compact car hot the debris two miles north of Valley of the Falls Drive, and there were no reports of any injuries, the CHP reported.

The 4.6 quake hit at 9:59 a.m. and the epicenter was reported between Big Bear City and Lake Arrowhead, according to automated earthquake sensors. More than 15 aftershocks rattled the mountains in the next hour.

A 3.4 magnitude quake was reported in the same approximate area just 55 seconds later, but it was not immediately clear if that was a separate quake or an echo detected by computers.

Fifteen minutes after the quake, the CHP closed the road at a section called ``The Arctic Circle,'' a landslide-prone section of road perched both above and below steep, vertical cliffs. It is one of three road accesses to Big Bear.

It was felt as a jolt at the CNS bureaus in Riverside and Palm Springs, and as a slight rumble at the CNS bureau in West Los Angeles. Scattered reports of feeling the quake were also noted by the USGS from Internet users as far south as San Diego.

There was no immediate report of any injuries or damage, according to Riverside County Fire Department.

The preliminary magnitude data came from automated sensors, and was subject to revision by seismologists.

Posted by Amy King