X0303 4 2010-03-11 0 0001130464 BLACK HILLS CORP /SD/ BKH 0001194294 OHLMACHER THOMAS M PO BOX 1400 RAPID CITY SD 57709 0 1 0 0 PRES & COO NONREG ENERGY GROUP Common Stock 2010-03-11 4 S 0 1070 29.00 D 52997.835 D Common Stock 2010-04-07 4 S 0 2101 32.00 A 50896.835 D Shares sold in accordance with 10b5-1 Plan dated November 5, 2009. Roxann R. Basham, by power of attorney 2010-04-08