A whole section of freeway in Northern California basically started sliding down a hill, and travelers on 101 in remote Humboldt County will be held up by a single-lane situation.

Caltrans crews are at work repairing a whole segment of sunken roadway in Humboldt County, along Highway 101 in Redwood National and State Parks, near Cooks Valley and the county border with Mendocino.

As the Press Democrat reports, nearly a mile of the freeway suffered some damage, including this section that caved in both sides of the two-lane road — and traffic is being limited to one lane, using only the undamaged eastern shoulder of the road.

"If the highway is open, it's safe," Caltrans said on Twitter. "Crews are conducting and planning stabilization efforts including the use of soil nails."

The "slip-out," as Caltrans is calling it, seems to have occurred between Monday and Tuesday, and the photos above were posted Tuesday morning.

Caltrans spokesperson Myles Cochrane reportedly told radio station KMUD that crews had been conducting 24-7 monitoring of the roadway and they still are, as work gets underway to shore up this collapsed section.

Elsewhere in Northern California, Caltrans has had its hands full handling other impacted roads in flooded Monterey County, cleaning up downed trees all over, and maintaining safety up in the snowy Sierra. Eastbound I-80 was once again closed early Wednesday with chain controls in effect for westbound traffic, but the freeway is back open in both directions.