Common Contracts

BLACK HILLS CORPORATION AND WELLS FARGO BANK, NATIONAL ASSOCIATION AS TRUSTEE SIXTH SUPPLEMENTAL INDENTURE DATED AS OF AUGUST 19, 2016 $400,000,000 3.150% NOTES DUE 2027 $300,000,000 4.200% NOTES DUE 2046

Supplemental Indenture • August 19th, 2016 • Black Hills Corp /Sd/ • Electric services • New York

• Contract Type
  Supplemental Indenture
• Filed
  August 19th, 2016
• Company
  Black Hills Corp /Sd/
• Industry
  Electric services
• Jurisdiction
  New York

SIXTH SUPPLEMENTAL INDENTURE dated as of August 19, 2016 (this “Supplemental Indenture”), to the Indenture dated as of May 21, 2003 (the “Base Indenture” and, as supplemented by the First Supplemental Indenture dated as of May 21, 2003, the Second Supplemental Indenture dated as of May 14, 2009, the Third Supplemental Indenture dated as of July 16, 2010, the Fourth Supplemental Indenture dated as of November 19, 2013, the Fifth Supplemental Indenture dated as of January 13, 2016, and as further supplemented, amended or modified, the “Indenture”), by and between BLACK HILLS CORPORATION, a South Dakota corporation (the “Company”), and WELLS FARGO BANK, NATIONAL ASSOCIATION, a national banking association organized and existing under the laws of the United States of America (as successor to LaSalle Bank National Association), as trustee (the “Trustee”).

BLACK HILLS CORPORATION AND WELLS FARGO BANK, NATIONAL ASSOCIATION AS TRUSTEE FIFTH SUPPLEMENTAL INDENTURE DATED AS OF JANUARY 13, 2016 $250,000,000 2.500% NOTES DUE 2019 $300,000,000 3.950% NOTES DUE 2026

Supplemental Indenture • January 13th, 2016 • Black Hills Corp /Sd/ • Electric services • New York

• Contract Type
  Supplemental Indenture
• Filed
  January 13th, 2016
• Company
  Black Hills Corp /Sd/
• Industry
  Electric services
• Jurisdiction
  New York

FIFTH SUPPLEMENTAL INDENTURE dated as of January 13, 2016 (this “Supplemental Indenture”), to the Indenture dated as of May 21, 2003 (the “Base Indenture” and, as supplemented by the First Supplemental Indenture dated as of May 21, 2003, the Second Supplemental Indenture dated as of May 14, 2009, the Third Supplemental Indenture dated as of July 16, 2010, the Fourth Supplemental Indenture dated as of November 19, 2013, and as further supplemented, amended or modified, the “Indenture”), by and between BLACK HILLS CORPORATION, a South Dakota corporation (the “Company”), and WELLS FARGO BANK, NATIONAL ASSOCIATION, a national banking association organized and existing under the laws of the United States of America (as successor to LaSalle Bank National Association), as trustee (the “Trustee”).