Glencross, SD

ZIP code 57630 serves Dupree, the county seat of Ziebach County, and surrounding rural areas in north-central South Dakota. The community lies within the Cheyenne River Indian Reservation, amid open prairie and widely spaced settlements. Its most prominent civic landmark is the Ziebach County Courthouse in Dupree; the surrounding reservation landscape and Cheyenne River region are defining features of the area.