Lake Oswego is a city located primarily in Clackamas County in the U.S. state of Oregon. Small portions of the city are also located in neighboring Multnomah and Washington counties. Located south of Portland surrounding the 405-acre (1.6 km²) Oswego Lake, the town was founded in 1847 and incorporated as Oswego in 1910. The city was the hub of Oregon's brief iron industry in the late 1800s and is today an affluent suburb of Portland. As of the 2000 census, the city had a total population of 35,278. The 2006 estimate is 36,350 residents.