Flames were burning pinyon-juniper and sagebrush on mostly rolling terrain a few miles southeast of Minersville. By Thursday afternoon firefighters had slowed its spread while changing weather was bringing a mixed bagged of conditions.
"The humidity seems to be higher, but the wind is stronger. We have a lot of thunder cells building overhead," Howell said. "The fire activity is pretty minimal now."
He said efforts were concentrated on building breaks around "two large fingers" extending from the main burn area with the goal of having them burn toward each other.
This blaze could become Utah's largest of the season. Currently it is second behind the 5,200-acre Antelope Fire near Cove Fort, which firefighters fully contained Wednesday. The 1,800-acre Wildflower Fire in Tooele County was fully contained Thursday.
A 20-member Logan-based Hotshot crew and a helicopter were corralling a fire that appears to have been started by a campfire early Wednesday outside Brigham City. At just 1.5 acres on timbered national forest land, the London Spire Fire was contained Thursday night, according to Forest Service fire information officer Kathy Jo Pollock.
Utah's fire season has been quiet compared with neighboring states, but officials are concerned that might change after a month with almost no precipitation and a week of triple-digit high temperatures. Last month, the BLM banned fireworks, exploding targets and steel core or jacketed ammunition on its land in Utah.
Recent research from the U.S. Forest Service's Fire Research Laboratory in Montana has found steel bullets can "reliably" ignite dried peat moss after striking a hard surface.
Bullet fragments can reach almost 1,500 degree Fahrenheit, the research found. Solid copper bullets were also prone to trigger flames, but they are not banned in the BLM order, which remains in effect indefinitely.
Enforcing a ban on particular kinds of ammunition might be hard, but officials said the shooting public has shown a strong interest in learning how to avoid igniting fires. Target shooting was implicated in many of the state's wildfires last year, including some that threatened homes.
"People are doing more checking and asking for safer places to shoot," BLM fire information officer said Heather O'Hanlon said. "Make sure you are not shooting in vegetation or into rocks. People are better about this stuff when it comes across their radar."
Pyrotechnics and tracer rounds have also been banned on national forests, as well as on state and private land in unincorporated areas.
Thunderstorms brought some moisture and cooler temperatures to northern Utah early Thursday, but they also delivered plenty of lightning strikes and wind gusts.
"Right now it's quiet. We have a couple winding down," O'Hanlon said at noon.
Sparked by lighting at 5 p.m. Tuesday, Black Mountain is the state's biggest hot spot. Two firefighters were sent to a hospital with heat-related illness Wednesday, and officials closed Chalk Hollow, Maple Springs, Black Mountain and Camel Hollow roads. A cabin was the only structure threatened.
Responsibility for fighting the fire, estimated to be just 35 percent contained, was handed to a Type III incident management team Thursday.