LOS ANGELES — Crews working around the clock cleared boulders, trees and crushed cars from all lanes of U.S. 101, but California officials said Monday the key coastal highway would remain closed for another week after being inundated during mudslides that killed 20 people.

Much of the water on the highway near the devastated town of Montecito had receded, allowing workers to use bulldozers and other heavy equipment to push away solid debris that was still several feet deep.

“It is not until you can see the damage with your own eyes that you can come to understand the magnitude of the incident, the response that is necessary, but most importantly the impact to the citizens and families of Santa Barbara County,” said Jim Shivers, a spokesman for the California Department of Transportation.

The number of people missing in the mudslides was cut to three Monday after a 53-year-old man was found safe.  John “Jack” Keating was located in Ventura with his dog Tiny, Santa Barbara County sheriff’s spokeswoman Kelly Hoover said.