The blaze threatened the observatory and communications infrastructure at the peak. Later, an observatory official said it appeared to be under control.

While fire officials said Thursday morning that growth of the 13,690-acre Eaton Fire has been significantly stopped, it continues moving north, reaching the peak of Mount Wilson where a Southern California transmission center is housed.

Authorities could not say what or how many structures are threatened by the spread, such as communication towers and the Mount Wilson observatory.