Manufacturing is the largest sector of Iowa’s economy, with $20.8 billion (21%) of Iowa’s 2003 gross state product. Iowa is the only state whose east and west borders are formed almost entirely by rivers. Iowa has more golf courses per capita than any other state. Countryaah.com: Offers a full list of nationwide and statewide holidays in Iowa starting from January 1st – New Year’s Day. Also covers the most recent three years of public holidays within the state of Iowa.