The Utah Department of Public Safety reports Hwy. 40 is closed between mile post 44 and mile post 80.
Drivers are urged to use SR-35 or US-191 as alternates.
The Dollar Ridge Fire has grown to 40,469 acres as of Wednesday morning.
The increase in acreage was reported by Utah fire officials Wednesday around 6:35 a.m.
On Wednesday afternoon, Wasatch County Emergency Management officials announced mandatory evacuations to all occupants of 40 Dam Acres, Pinehollow, Aspen Grove campground and Aspen Grove Marina.
"We need all the citizens in these areas to please evacuate immediately due to the fire changing direction," a Facebook post by Wasatch County Emergency Management said.
On Wednesday evening, fire officials clarified that the evacuation order does not affect the area north of Hwy. 40, from the Strawberry Reservoir to Currant Creek.
"Wasatch County officials have stated that they are evaluating the evolving fire conditions to see if they need to order a mandatory evacuation. It has not been ordered as of yet. The mandatory evacuation order from the Wasatch County Sheriff's Office fro the Pine Hollow sub-division remains in effect," a statement from the Great Basin Interagency Management Team said.
Hundreds of other homes had already been evacuated Tuesday.
A community meeting is planned for Thursday, July 5 at Duchesne High at 7 p.m.
"Multiple representatives from the affected land areas will be in attendance to answer questions," a Facebook post from Utah Fire Info said.
The American Red Cross has set up a shelter at Duchesne High School to help anyone affected by the fire and the evacuations. Officials say the Duchesne County Fairgrounds' livestock area is now home to more than a dozen horses and about 30-40 dogs and cats, with room for more evacuated animals as the emergency continues.
Many evacuated residents are gathered at a local gas station to keep an eye on the progress of the fire.
Tom Clyde's parents live in Fruitland and were among those evacuated. He's keeping an eye on their property.
"Yesterday morning I thought we were OK, and then yesterday afternoon the winds were coming in—we were pretty worried last night," Clyde said. "[Wednesday] morning it looks a little better... There's still hope, everything's looking OK this morning."
The Utah Department of Transportation says US 40 remains open Wednesday, but they say they are monitoring the situation and a closure is possible if fire activity shifts.
The Type 1 Great Basin Incident Management Team has also arrived to take over management of the fire from the Type 2 team that has been on site.
As of Wednesday morning there 12 crews, three engines, 10 helicopters, two dozers and a total of 402 personnel fighting the fire.
Crews at the scene estimate that dozens of structures have been destroyed so far, but they say they can't confirm an exact number because the area is deemed to dangerous to do a proper damage assessment.
Strong winds have complicated fire fighting efforts and limited the ability of ground crews to maintain fire lines or for aerial resources to make retardant drops.
"Once again fire crews, who had been making progress in establishing an anchor point and construction of containment lines, had to withdraw from the line in several areas with the most fire activity along the north and northeastern edges of the fire for safety reasons," a press release from fire officials stated of Tuesday's weather conditions.
Wednesday, a temporary flight restriction was issued for a 12 square mile area over the fire up to an altitude of 12,500 feet above sea level.
"This means no civil aviation or hobby aircraft such as drones are allowed in the restricted air space," the release stated.
Gov. Gary Herbert declared a "State of Emergency" Tuesday due to the high fire danger in the Beehive State.