Ohio 339 was closed for about a half hour after a load of hay caught fire in a pickup truck around 4 p.m. Sunday.
The truck driver's name was not released, but fire officials said no one was injured during the incident.
Between 15 and 20 firefighters responded to the blaze with three units from the Watertown and Barlow volunteer fire departments.
Barlow VFD Chief Troy Eddleblute said the Dodge pickup had a load of hay in the bed and was towing a trailer with a second hay load when the blaze occurred.
In addition to the hay, the truck's rear tires were also destroyed by the fire.
Eddleblute said the cause of the fire was not known.