 Matawan Creek's main flow begins as Bakers Brook in Marlboro Township, Monmouth County, north of the intersection of Tennent and Woolleytown Roads.From this point it flows northward through Marlboro and Aberdeen Townships to a point near the Middlesex County line, where it turns in a northeasterly direction.Birch Swamp Brook enters from the right; below this confluence is the impoundment, Lake Lefferts.