SCOFIELD, Carbon County — A wildfire ignited by lightning last weekend in southeast Utah County has quickly grown to 14,700 acres and threatens homes, power lines, rail lines and a highway.
Due to heavy smoke Thursday afternoon, fire officials closed both directions of U.S. 6 from Thistle turnoff to Sheep Creek Road for about an hour. The road reopened shortly before 6:30 p.m.

Officials cautioned anyone driving U.S. 6 to travel slowly and turn on their lights for visibility in the area "where fire traffic will be heavy" at the intersections of U.S. 89 and Dairy Fork Road.
Areas of Utah, Sanpete and Carbon counties are under evacuation orders, and many residents who are not yet evacuated have been told to prepare to leave their homes if the need arises.
Utah County evacuated Sheep Creek Road and campground as the fire continued to develop Thursday afternoon.
Some residents of Wasatch County have also been asked to prepare to evacuate.
"We're right on the border of the fire. It's burning toward us right now," said Carbon County Sheriff Jim Wood.
He said officials' "first concern" is making sure people and their livestock are out of danger and then protecting structures.
The blaze, dubbed Coal Hollow Fire, was 0 percent contained Thursday.

A map of all areas under evacuation and pre-evacuation orders can be found on the Incident Management Team's website at inciweb.nwcg.gov/incident/6101/.
Almost 220 firefighters are trying to wrangle the fire, which is burning in brush, hardwood slash, chaparral and timber.
The fire is expected to continue "extreme fire behavior" due to the hot, dry weather, according to fire officials.

Firefighters' goals Thursday included constructing fire lines, protecting structures and keeping the fire south of U.S. 6.
While firefighters work to slow the spread of the Coal Hollow Fire, those fighting the nearby Hill Top Fire have noted progress. Residents of the Milburn area were allowed to return home Thursday, and others under evacuation will be able to return home Friday morning "if the suppression efforts continue to be effective," according to the Sanpete County Sheriff's Office.

The Hill Top Fire is burning about 1,800 acres and was 61 percent contained Thursday.
Lt. Gov. Spencer Cox, who lives just a few miles away from the fire in Fairview, has taken to Twitter since the fire began to share updates.
"The worst appears to be over. I love our small community and the way we respond together in the face of danger and tragedy. There is nowhere in the world I would rather live," he tweeted Thursday morning.
An evacuation center set up by the Red Cross in the LDS chapel in Indianola, Sanpete County during the Hill Top Fire remained open through Thursday, according to Red Cross officials.
The Incident Management Team fighting the Coal Hollow Fire held a community meeting Thursday at North Sanpete High School in Mt. Pleasant.
In a Q&A session at the end of the meeting, community members asked about expected fire activity, when they might be able to return to their homes and how they can stay updated on the fires.
Officials told them they can find current information by visiting the Incident Information website.
Impacts from the blazes aren't limited to the immediate area.
Utah's Division of Air Quality warned residents across most of the state that "smoke from wildfires could cause high concentrations of particulates in populated areas. If smoke becomes thick, persons with existing heart or respiratory ailments should reduce physical exertion and outdoor activity," the division said.