SAN FRANCISCO -- With a stormy weekend on the way, residents in San Francisco's Telegraph Hill neighborhood are among many Bay Area residents casting a wary eye on the region's already rain-saturated hillsides.

A slide on the eastern cliff face of Telegraph Hill was discovered by a parking control officer making her rounds in the neighborhood at 5 p.m. Wednesday. Police quickly cordoned off the area.

"We came out and saw rocks falling from beneath the building (perched on the hillside)," said Lt. James Caloncio. "We called in the city engineers."

Several homes and apartments were evacuated while the engineers combed the hillside, testing its stability. When it was determined the cliff was secure for now, residents were allowed to return.

"These hills are in motion, unfortunately," said local resident Stan Hayes. "I'm very surprised and sorry to see it. This looks awful."

However, San Francisco Supervisor Aaron Peskin, a resident of the neighborhood, said there was no need for immediate concern.

"The reality is that this is the edge of an old quarry," he said. "When it rains, rocks move. This is a relatively superficial slide. We had geotechnical engineers out and they said the rock is quite solid."

Elsewhere, a series of slides had transformed Highway 1 just north of Jenner into a muddy mess. Crews worked overnight to clear the roadway.

"There's probably 10 to 15 slides covering anywhere from a quarter of the lane to two thirds of the road," said Steve Baxman of the Monte Rio Fire Department.

The slides throughout the Bay Area made for a busy day for Caltrans crews.

"We have crews that are standing by 24 hours a day, we have a loader parked around the corner for quick response and our plow trucks are always on the road," said Dave Nelson, a Caltrans maintenance supervisor.

Residents on the San Mateo coastline kept a nervous vigil on Highway 1's notorious Devil's Slide.

"There's been a lot of slides in the past," said Montara resident Robyn Graham. "It's very nerve-racking. You always wonder when it is going to come down."

Meanwhile, the state Department of Conservation urged residents Thursday to keep an eye out for potential landslide warning signs for those with homes below steep slopes.

"Most Californians are aware that we live in earthquake country, but landslides can be every bit as dangerous as temblors," John Parrish, head of the DOC's California Geological Survey, said in a statement.

"Fortunately, unlike earthquakes, landslides sometimes give warning signs that residents can identify in order to protect the safety of their homes and families."

A landslide is considered to be any mass of earth and rock that moves downhill by sliding, flowing or falling. Mudslides, which move more rapidly than landslides, often travel between 10 mph to 100 mph, the DOC reported.