Hazmat crews responded to a crash along Interstate 40 West near the McDowell-Burke County line Thursday.
Officials say a tanker truck hauling milk ran off the right shoulder near Exit 94 at Dysartsville Road and overturned. The tanker separated from the truck, falling down an embankment into Muddy Creek, while the truck remained on the bridge above.
The driver, who was the only person in the vehicle, was not injured.
The roadway was closed for several hours early Thursday. One lane reopened around 8:15 a.m., with both lanes back open and traffic returning to normal by about 6:25 p.m., according to McDowell Emergency Management.
Crews from multiple counties, along with a regional hazmat team and state environmental officials, worked throughout the day to contain the spill.