| # | Institution | Type | Branches | Deposits | Share |
|---|---|---|---|---|---|
| 1 | First Interstate Bank | Bank | 2 | $115.2M | 36.08% |
| 2 | Black Hills Federal Credit Union | Credit union | 1 | $100.6M* | 31.50% |
| 3 | Highmark Federal Credit Union | Credit union | 1 | $46.8M* | 14.67% |
| 4 | Dacotah Bank | Bank | 1 | $35.6M | 11.16% |
| 5 | Sentinel Federal Credit Union | Credit union | 1 | $21.0M* | 6.58% |
* Credit-union deposits are estimated (June total shares spread evenly across branches).
| Year | Deposits | Institutions | Branches | Leader | Top share | HHI |
|---|---|---|---|---|---|---|
| 2025 | $319.2M | 5 | 6 | First Interstate Bank | 36.1% | 2,677 |
| 2024 | $292.9M | 5 | 5 | Black Hills Federal Credit Union | 34.2% | 2,569 |
| 2023 | $327.5M | 5 | 5 | Black Hills Federal Credit Union | 38.2% | 2,675 |
| 2022 | $337.9M | 5 | 5 | Black Hills Federal Credit Union | 39.4% | 2,784 |
Every institution above links to its profile — ratios, peer medians and this quarter’s change signals. Pro adds the full table, share movement and CSV export.