The firenado, or fire whirl, was caused by the Tennant Fire which started June 28 on the eastern side of the Klamath National Forest near Highway 97 in Siskiyou County, California.
As of Wednesday, the fire had ripped through more than 10,000 acres and was 71% contained.
Firenados occur when ground-level winds come into contact with a fire.
The U.S. Forest Service captured the footage on June 29 while battling the fire.
The weather service's office in Medford, Oregon, said meteorologists noticed the rotation on June 29 and shared a radar image as further proof of the incident.
Evacuations remain in place.
The cause of the fire is under investigation, the Forest Service said.