Shannon County is a county located in the U.S. state of South Dakota. The population was 13,586 at the 2010 census. Its largest community is Pine Ridge. Shannon County does not have its own county seat. Instead, Hot Springs in neighboring Fall River County serves as its administrative center.
The county is entirely within the Pine Ridge Indian Reservation and contains part of Badlands National Park. It is one of five South Dakota counties entirely on an Indian reservation. (The others are Corson, Dewey, Todd, and Ziebach.) The county's median household income makes it the forty-eighth poorest county in the United States. (Kalawao County, Hawaii, is the poorest .)
Note: Created before 1880; included with Pine Ridge Indian Reservation in 1890-1910; reported in 1920-90.