1. Press Release (full text ) [November 17, 2021]
2. Press Release (full text ) [October 29, 2021]
3. Press Release (full text ) [March 29, 2016]
4. Swisher, Kaija. Black Hills Pioneer [May 26, 2015]
5. Press Release (full text ) [November 10, 2010]
6. Press Release (full text ) [July 15, 2010]