The Doerner Fir is over 325 feet tall. Its top has been burning since Aug. 17, but lightning, the most obvious cause, has been ruled out.

Crews are working to douse blaze on the 325-ft Doerner fir, one of the tallest non-redwood trees in the world

With about 50 ft already lost, the fire may impact the Doerner Fir's standing in global height rankings, officials say.

The Doerner Fir is over 325 feet tall. Its top has been burning since Aug. 17, but lightning, the most obvious cause, has been ruled out.