Spirit Lake in Dickinson County, Iowa, is the largest natural lake in Iowa, covering approximately 5,684 acres with an average depth of 17 feet and a maximum depth of 7 meters. This eutrophic lake features a relatively uniform basin with about 15 miles of shoreline, much of which has been developed for residential and recreational use. The lake is part of the Iowa Great Lakes chain and supports a diverse recreational fishery year-round. Known locally as "Big Spirit Lake," it offers abundant near-shore structure and several bays and coves that remain fishable even when wind whitecaps the main body of the lake. Water clarity has improved in recent years, increasing aquatic plant diversity and density, which has positively affected fish populations.