PLUMMER — Highway 5 between Plummer and St. Maries is on the move.

The highway 6 miles east of Plummer could be shut down for about a week because the road is shifting, likely because of wet conditions, said Mike Lenz of the Idaho Transportation Department.

"It's an active slide," Lenz said. "The cracks have grown to 10 inches wide and a minimum of 2 feet deep. It looks like an earthquake happened."

The cracks, he said, were 3 inches wide on Tuesday, and ITD shut down the highway late Tuesday night due to safety concerns.

"We had guys out manning it," Lenz said. "We had an idea that this was coming. The best-case scenario is a week for opening it back up."

Lenz said the shifting is likely the result of saturated ground.

"It's a tough clay that's in there and clay loves water," he said. "It absorbs water like a sponge. Clay gets extremely slick and rock on top of that clay could be sliding.

"That's the theory until we get core samples."

Lenz said the samples are the first priority before repairs start.

"We don't know what to do until we get information to come up with a game plan," Lenz said. "You hate to rush to conclusions and tear up the road when you don't know what's underneath."

Residents who live along Highway 5 are still allowed to use the road except along the quarter-mile stretch that's shut down. Commercial traffic, meanwhile, is being diverted at Plummer and St. Maries and using Highways 3 and 6 as alternate routes.

"We don't want any commercial vehicles on Highway 5 because we don't want it to get bottlenecked up," Lenz said.

The road is closed on Peedee Hill where there are no homes.

"We got lucky that way," Lenz said.

ITD crews have been responding to rockslides throughout the region for the past week, Lenz said. One the agency is still monitoring is along Highway 97 just north of Harrison.

"We've had a lot of slides because it has been so wet," Lenz said.