A blaze in Dewey County took firefighters seven hours to get under control.
The fire injured at least four people, including three firefighters.
One firefighter was flown to Oklahoma City to be treated for burns to his arms and legs.
One female landowner and a firefighter were treated for smoke inhalation.
Officials said attempts to distinguish the fire were slowed by water supply problems, terrain issues and high winds.
The fire was fought by six different fire stations from Beaver, Ellis, Custer, Woodward and Dewey counties.