Let KAYAK do the searching
Based on KAYAK hotel searches, the most popular destination is Rapid City (50% of total searches to South Dakota). The next most popular destinations are Yankton (25%) and Watertown (13%). Searches for hotels in Keystone (13%) are also popular.
KAYAK users have found double rooms in South Dakota for as cheap as R1 253 (Brookings) in the last 3 days. The average price is R3 568.