An additional 1,700 acres have burned in Beaver County since the Baboon Fire flared up Friday.
The fire was thought to be contained earlier this week, but investigators believe a single tree inside previous containment lines caught fire and ignited extremely dry vegetation nearby.
The new flare-up was 50 percent contained Saturday. With the additional burnt land, the Baboon Fire is estimated to have blackened 20,732 acres since it was initially sparked July 13.
The fire is burning about six miles south of Minersville, and was caused by lightning.
No structures have been damaged and no injuries have been reported.
The Lighthouse Fire in Emery County was 85 percent contained Saturday, and officials said the fire had burned through 862 acres. Fire officials determined the wildfire was human-caused.
Several archaeological sites were threatened by the Lighthouse Fire, including rock art, granaries, pit and cliff dwellings, burial sites and other points of archaeological interest along Range Creek.