found: Duvernoy, E. Jamesport transmission exits ... 1976:t.p. (Town of Riverhead ... New York)
found: Rand McNally comm. atlas & marketing guide, 1982(Riverhead, Town of, Suffolk County; contains Riverhead village and other popl. places)
found: LC database Jan.11, 1984(hdg.: Riverhead, N.Y.; variant: town of Riverhead)
found: GeoNames, algorithmically matched, 2009(ppl; 40°55ʹ01ʺN 072°39ʹ43ʺW)
found: Wikipedia, Mar. 28, 2013(Riverhead (town), New York; The town of Riverhead is in Suffolk County, New York, on the north shore of Long Island. Riverhead is the county seat of Suffolk County. There is also a smaller hamlet of Riverhead, which lies in the town; Town of Riverhead; 40°55ʹ42ʺN 72°39ʹ44ʺW)