0001104659-09-059872 8-K 1 20091022 8.01 20091022 20091022 BLACK HILLS CORP /SD/ 0001130464 4911 460458824 SD 1231 8-K 34 001-31303 091131112 625 9TH STREET PO BOX 1400 RAPID CITY SD 57709 6057212343 625 9TH STREET PO BOX 1400 RAPID SD 57709 BLACK HILLS HOLDING CORP 20001222 8-K 1 a09-31821_58k.htm 8-K