Police say the driver was trying to ease the rig to the side of U.S. Highway 2 on Friday morning. The wheels of the truck slipped down an embankment and dumped its contents - 49 tons of river sediment.
State Trooper Keith A. Leary says the driver apparently was unfamiliar with the area. Filling stations and other businesses with restrooms were a few miles away.
The 27-year-old was cited for driving with wheels off the road. Leary says the trucking company will be billed for the cleanup.
