MONDAY UPDATE: The fire was 75 percent contained at 76 acres, Cal Fire reported.
Fresno County firefighters are on the scene of a 50- to 60-acre fire near Tivy Mountain east of Sanger on Sunday night.
There is currently lightning in the area and heavy wind, said Fresno County Fire Capt. Jeremiah Wittwer.
The cause of the fire and when it started was unknown.