Genesee Park is a 57.7-acre (0.234 km2) park in the Rainier Valley neighborhood of Seattle, Washington. A waterway, Wetmore Slough, before the lowering of Lake Washington by nine feet in 1917 as part of the construction of the Lake Washington Ship Canal, it was purchased by the city in 1947 and used as a dump until 1963. Development of the park began in 1968. It hosts the hydroplane races and aerobatics air show during the annual Seafair, in July–August.