Iroquois is a city on the border of Beadle and Kingsbury counties in South Dakota, United States. The population was 292 at the 2020 census. …Iroquois is a city on the border of Beadle and Kingsbury counties in South Dakota, United States. The population was 292 at the 2020 census. The school building is located in Kingsbury County, while the school parking lot is located in Beadle County. Highway 14 runs directly through Iroquois.