The local zip code mailing address of "Greater Upper Marlboro", however, covers 77 sqmi of territory and includes additional areas west and south of the red area, extending from the Capital Beltway (Largo, Westphalia, and New Orchard areas) on the west to the Patuxent River/county line on the east, and far southward into the rural Croom and Nottingham, Naylor, and Rosaryville areas (greatly below the map's red area).