Reston, Virginia, United States [CDP]; population was 48,556 in 1990; housing units was 19,999 in 1990; location is 38°57'N 77°21'W; land area is 17.24 square miles (11,033 acres); water area is 0.14 square miles (92 acres); FIPS code is 66672 [SourceCBP]