Sparked just after 6 p.m., the cause of the fire was still under investigation, Pollock said.
Pollock said a fire crew of 24 people would likely work through the night. She said there was no reported lightning in the Davis County area when the blaze began on the steep hillside.
Pollock said the fire was burning through thick oak brush, moving north and east, and was heading uphill but was about 300 yards away from any nearby structures.
She said canyon winds and tough terrain could prove to be problematic as crews work on the steep hillside.
"It's in such steep, heavy country," she said. "These guys will probably be working through the night."
Elsewhere, the Pine Canyon Wildfire started at about 3 p.m. Friday and spread to 375 acres as it burned in high-desert grass and brush in remote northwestern Utah, about three miles east of the tiny Box Elder town of Grouse Creek. The cause is under investigation.
Meanwhile, U.S. Forest Service fire information officer Kim Osborn said the Pumpkin Fire, ignited by lightning Friday shortly after thunderstorms moved through the region, had burned 176 acres one mile north of Highway 6 in Utah County's Spanish Fork Canyon. It was 30 percent contained Saturday night with three helicopters dumping water and 105 firefighters working on it.
A few cabins were near the road in the path of the fire, but not in immediate danger.
"If things work well, they will get a good handle on it," Osborn said.
Sheep Creek Campground is closed not because of the fire, but due to crews using it as a base for their helicopters, Osborn said.
No homes were threatened, and no injuries had been reported in either of the new fires.
Late Friday, crews declared full containment of the 43,610-acre Dallas Canyon Fire. It is expected to be fully controlled meaning no hot spots inside the containment line by Aug. 5.
Grass, brush and pinyon in the Cedar Mountain Wilderness Area had been ablaze since lightning ignited the wildfire on July 27, according to Lee.
Yet another lightning-caused blaze, the 410-acre North Hills Wildfire burning two miles northwest of the Washington County town of Enterprise, was fully contained Friday night.