Let KAYAK do the searching
Based on KAYAK hotel searches, the most popular destination is Rapid City (56% of total searches to South Dakota). The next most popular destinations are Pierre (17%) and Sturgis (17%). Searches for hotels in Box Elder (11%) are also popular.
KAYAK users have found double rooms in South Dakota for as cheap as $58 (Deadwood) in the last 3 days. The average price is $312.