Firefighters from across the country expected no help from the weather on Saturday as they battled a remote, fast-moving 61,000-acre blaze in Texas.
A huge, dark thunderhead of smoke visible for miles hung over Stonewall County in northern Texas as ranchland burned, the Texas Forest Service said.
Wildfires fed by dry, windy conditions have charred more than 82,000 acres over seven days across the state, killing livestock, destroying buildings and drawing in crews and equipment from 25 states.
"Predicted fire weather for tomorrow is even worse," Forest Service spokesman Alan Craft said. "These are the worst conditions we have ever seen."
The state forest service has helped fight 92 fires in the past week.
Plants that thrived in wet weather last year have dried to tinder under a drought covering all of Texas, and weeks of high winds and little moisture have made every spark dangerous.
Sparks thrown by pipe cutting in Stonewall County lit a sprawling fire in rugged terrain, Craft said.
The blaze moved 12 miles in less than four hours on Friday, despite 58,000 gallons of fire retardant dumped from helicopters and the efforts of bulldozers and firefighters from as far away as Montana and Washington on the ground.
Almost 170 head of cattle were reported killed and four unoccupied homes were destroyed, Forest Service information officer Mary Kay Hicks said.
Portions of the fire had run out of fuel, helping crews on Saturday before winds began to pick up again, she said.
"They made progress, but the wind is fighting against them."
Temperatures were in the mid-90s, with winds gusting up to 35 miles per hour, said National Weather Service meteorologist Robert Barritt.
Sunday was expected to be worse, with wind gusts of up to 50 miles per hour, but Barritt said winds should die down by Monday afternoon after a cold front passes through.