 On December 12, 2001, Cao Phong District was formed from a portion of Kỳ Sơn District.On December 17, 2019, Kỳ Sơn District was annexed by the city of Hòa Bình.Mường (63.4%) is the major ethnic group of Hòa Bình Province, followed by Kinh (27.7%).