The state says an Upper Peninsula fire has pushed past fire lines and grown to more than 12,000 acres.
Erratic winds, temperatures in the 80s and a lack of rain are leading to the spread of the fire.
The new estimate from the Michigan Department of Natural Resources makes it larger than the 5,625-acre Tower Lake fire in 1999, another big U.P. blaze.
No injuries have been reported.
The fire was about six miles north of Newberry in Luce County, and about 10 miles from Tahquamenon Falls State Park.
State route 123 remains remains closed. Precautionary evacuations were order for part of Luce County Road 420.