Highway 140 only has one lane open, with traffic control points from the Yosemite Bug Hostel to Briceburg Road, due to the Colorado Fire.
County officials are hoping the fire will be contained and the road fully open by this weekend so tourists can travel smoothly for the Mariposa County Fair.
The fair kicks off Friday, and organizers say the rides and barns are ready to welcome guests.
Fire officials are telling everyone to expect delays and to be aware of fire crews and equipment in the roadway.
It lasts through Monday at the Mariposa Fairgrounds.