Fire crews reigned in the North Cottonwood Fire in Cache County on Wednesday afternoon.
The fire burned 80 acres about 12 miles east of Hyrum, in Blacksmith Fork Canyon, said fire spokesman Jason Winn.
Two hotshot crews finished mopping up the fire about 3 p.m., Winn said.
Investigators aren't sure yet what sparked the blaze.
The flames had threatened some power lines and seasonal trailer homes on the west side of the fire, but crews were able to contain that side before any damage occurred, Winn said.