Lake Oswego, Oregon, United States [City]; population was 30,576 in 1990; housing units was 13,110 in 1990; location is 45°25'N 122°42'W; land area is 9.54 square miles (6,104 acres); water area is 0.61 square miles (388 acres); FIPS code is 40550 [SourceCBP]