Fonda, Iowa – The Sunken Grove and Leo Shimon Marsh Wetland Complex becomes Grand Central Station twice a year for migrating ducks, geese, pelicans and shorebirds that stop to rest and refuel before resuming their journey. The nearly 1,300 acres of wetlands, marshes, prairies and timber is surrounded by some of the most productive farmland in the world in southwest Pocahontas County.