Ridgefield is a city in northern Clark County, Washington, in the United States. The population was 4,763 at the 2010 census. Located within the Portland metropolitan area, Ridgefield is notable for the significant Native American history and connection to the Lewis and Clark Expedition. It is also the headquarters of the Ridgefield National Wildlife Refuge, a primary reserve for migrating waterfowl on the Pacific Flyway, and the home of the Ridgefield High School "Spudders" (reflecting the area's potato-farming heritage).
The area has important ties to the Lewis and Clark Expedition of 1804–1806, being close to the Chinookan town of Cathlapotle, then a settlement of 700–800 people, with at least 14 substantial plank houses. The community's ties to the Chinookan people was commemorated by the construction of a replica of a Cathlapotle plank house at the nearby Ridgefield National Wildlife Refuge, which was dedicated March 29, 2005.
The town was formerly known as Union Ridge, named by the many Union veterans among the first large wave of settlers after the Civil War and was renamed Ridgefield in 1890. The town's original name is preserved in the name of Union Ridge Elementary School.
Ridgefield was an important trading center as early as the 1860s with its key location near the mouth of the Columbia River, and the city was officially incorporated on August 26, 1909. U-Haul, an American equipment rental company, had its start in Ridgefield in 1945.
According to the United States Census Bureau, the city has a total area of 7.18 square miles (18.60 km2), of which 7.08 square miles (18.34 km2) is land and 0.10 square miles (0.26 km2) is water.
Parks in Ridgefield include Abrams Park, Community Park, Davis Park, and Overlook Park. The Ridgefield Veterans Memorial is adjacent to Community Park. Jefferson Davis Park, a private park just outside Ridgefield, serves as a Confederate memorial.