Busy fire crews in Box Elder County extinguished one blaze late Wednesday and contained three others that continued to burn Thursday near Park Valley. Also Thursday, crews battled fires in Tooele County and Millard County.

The Matlin, Peplin and Bar H fires in the area south and west of Park Valley in Box Elder County were all caused by lightning. The Matlin Fire burned along the historic railroad, taking out two of the historic railroad trestle bridges. Several other recreational structures (three cabins, five trailers and a couple of outbuildings) were threatened, but crews were able to save the structures and contain the fire, which is estimated at 8,000 acres.

The Peplin and Bar H fires are estimated at 1,000 acres and 1,352 acres, respectively, and no structures are threatened.

The Golden Spike Fire — which burned directly across from Golden Spike National Historic Park — was ignited by a local farmer using a cutting torch while installing a gate. The farmer used his tractor to help firefighters contain the fire, which burned about 2 acres before it was extinguished.

The Pacific Fire, burning near mile marker 55 along I-15 in Tooele County, has scorched 267 acres. The cause of the fire is unknown. In Millard County, the Antelope Road Fire has burned 388 acres.

Most of Utah will be under a Red Flag Warning through Friday as high temperatures continue before possible thunderstorms make their way into the area late Friday. Storms may produce gusty winds, small hail and heavy rain.

A second storm system will move into northern and central Utah on Sunday into Monday, bringing another round of precipitation and a chance of snow in the mountains and mountain valleys.