From parts of Bienville Parish, Bossier Parish, Caddo Parish and Natchitoches Parish. Named for the Red River , which is part of the Mississippi River watershed 7,420. Coordinates: 30.184507°N 91.119770°W Belle Grove, also known as Belle Grove Plantation, was a plantation and elaborate Greek Revival and Italianate -style plantation mansion near White Castle in Iberville Parish, Louisiana.