(Big Sur, California.Shutterstock)

California Highway 1 is the longest route in the state, stretching 655 miles down the coast. The road offers pristine ocean views. Songs have been written in its honor.

But a series of landslides earlier this year swallowed up swaths of the highway in and around the ever popular Big Sur region. A mudslide on May 20 spewed 1 million tons of rocks and debris onto the highway and the cliff beneath it.

Here's what the road looked like in March and in late May:

(Planet.com and Diana Yukari/Business Insider)

The massive landslide wiped out one-third of a mile in an area called Mud Creek, on the southern end of the Big Sur coast. Early estimates say it may take as much as one year and millions of dollars to clear the rubble and rebuild that patch of Highway 1, The Mercury News reported.

"This is by far the worst we've ever seen," Susana Cruz, a spokeswoman for the California Department of Transportation, told The New York Times in May.

The mudslide was so severe that the damage could be seen from space. NASA's Earth Observatory in May released satellite images that capture the devastation:

(NASA's Earth Observatory)

California experienced one of its wettest seasons on record over the past year, which made the collapse somewhat predictable — though no less staggering.

The local radio station KQED reported that some highland locations around Big Sur received about 117 inches of rain between October 2016 and April 2017, and the mountainside was soaked through.

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The rain has stopped, but the area remains dangerous. Tourism revenue in Big Sur has stumbled since the slides began earlier this year. Wealthy visitors are being helicoptered in.

Check out other views of the damage:

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