Let KAYAK do the searching
Based on KAYAK hotel searches, the most popular destination is Rapid City (57% of total searches to South Dakota). The next most popular destinations are Mitchell (17%) and Pierre (13%). Searches for hotels in Sturgis (13%) are also popular.
KAYAK users have found double rooms in South Dakota for as cheap as $107 (Sioux Falls) in the last 3 days. The average price is $309.