Utah Fire Info first reported the fire shortly before 6 p.m. July 28.
Park City Fire Battalion Chief Mike Owens says crews were able to keep the fire to about 1,600 square feet.
He says the most likely cause was a bird flying into a transformer and then falling to the ground, which ignited the grass.
No power outages were reported, nor injuries, apart from the bird.
Both Park City firefighters and mountain employees responded to and contained the flames shortly after it sparked.
