(Guthrie-AP) -- As many as 40 fire departments fighting a wildfire in the Arbuckle Mountains have been joined by U-S Forest Service firefighters.
Air tankers and helicopters from Oklahoma, Texas and Kansas have dumped tons of water on the 17 wildfires.
Emergency management officials say nearly 40-thousand acres since last Friday.
The fire in the rugged mountains is the largest of more than 100 wildfires that have raged across the state.
The southbound lanes of Interstate 35 north of Davis were closed for a time when a grass fire jumped into the median.
Agriculture Department spokesman Jack Carson said investigators believe many of the fires have been arsons, started by carelessly thrown cigarettes, fireworks and other burning items thrown onto dry grass.
At least 60 homes across the state have been damaged or destroyed by the fires.