The Upcounty Regional Service Area is the largest of the five centers with 250 sq. miles or one-half of the County's land area. The Center's service population is approximately 300,000 people in several communities including Gaithersburg, Germantown, Clarksburg, Damascus, Goshen, Laytonsville, Derwood, North Potomac, Darnestown, Boyds, Montgomery Village, Barnesville, Dickerson, Poolesville, Washington Grove, Beallsville, Hyattstown and Tobytown.