RIO VISTA, Calif. -- Crews are battling a vegetation fire that is burning in east Solano County at state highways 12 and 113 west of Rio Vista. The fire started Wednesday afternoon.The Montezuma Fire Protection District responded to the three-alarm fire that reportedly has burned at least 50 acres, according to posts on Facebook.The fire in an area where windmills are located was reported around 3:30 p.m., according to the California Highway Patrol. The CHP issued a Sig-alert at 4:30 p.m.The fire is burning on both sides of Highway 12 and eastbound Highway 12 is closed at Olsen Road, the CHP said.Smoke from the fire can be seen in the Fairfield area, fire officials said.