The Metropolitan Area EMS Authority, known as MedStar, is the exclusive emergency and non-emergency ambulance service provider to 15 Tarrant County cities including Blue Mound, Burleson, Edgecliff Village, Forest Hill, Fort Worth, Haltom City, Haslet, Lakeside, Lake Worth, River Oaks, Saginaw, Sansom Park, Westover Hills, Westworth Village, and White Settlement. MedStar provides advanced life support ambulance service to 434 square miles and more than 980,000 residents in Tarrant County and responds to about 135,000 emergency calls a year with a fleet of 57 ambulances.