| Relationships | Role | Relationship Start | Relationship End |
| First Interstate Bancsystem, Inc. | Parent | 8/6/1999 | 8/31/1999 |
| Security State Bank Shares | Parent | 10/1/1980 | 8/5/1999 |
| Acquisitions & Mergers | Role | Assets | Acct Method | Type | Transaction Date |
| First Interstate Bank | Buyer | 8,944,669 | Pooling of Interests | Discontinued | 9/1/1999 |