- Ilwaco is located on Baker Bay in Pacific County, at the confluence of the Columbia River and the Pacific Ocean – the south end of the Long Beach Peninsula. Ilwaco owed its early development to its location – it was a transportation hub for travelers arriving by ferry and making their way on up the Long Beach Peninsula, which was (and is) a popular vacation destination. Fishing is another major industry. Ilwaco incorporated in 1890, and became a city on July 13, 1987. The population of about 1,000 swells to 3,000 during the summer months, when vacationers arrive for swimming, boating, fishing, and other recreation.