Cleanup crews made quick work of a trail of nails spilled Monday afternoon along Highway 40 between Whitefish and Columbia Falls.
One lane was opened as of 3:45 p.m., and both lanes were cleared for traffic 15 minutes later, according to the Montana Highway Department.
MDT said someone dumped or dropped boxloads of nails in several different locations along a 4-mile stretch.
At one point the highway was shut down between U.S. Highway 93 south of Whitefish and Hilltop Road on the outskirts of Columbia Falls.
"It has been deemed too hazardous for travelers to use the roadway," an advisory from MDT said at 2:45 p.m. Monday, about an hour after the first report came in.
MHP and the Flathead County Sheriff's Department were on the scene with the nails coned off, and MDT crews assisted with the cleanup. The suspect vehicle remained unknown.