| # | Institution | Type | Branches | Deposits | Share |
|---|---|---|---|---|---|
| 1 | The Yellowstone Bank | Bank | 2 | $200.9M | 54.10% |
| 2 | First Interstate Bank | Bank | 2 | $72.6M | 19.55% |
| 3 | Altana Federal Credit Union | Credit union | 1 | $53.6M* | 14.44% |
| 4 | Valley Financial Credit Union | Credit union | 1 | $44.3M* | 11.91% |
* Credit-union deposits are estimated (June total shares spread evenly across branches).
| Year | Deposits | Institutions | Branches | Leader | Top share | HHI |
|---|---|---|---|---|---|---|
| 2026 | $371.5M | 4 | 6 | The Yellowstone Bank | 54.1% | 3,659 |
| 2025 | $344.5M | 4 | 6 | The Yellowstone Bank | 54.4% | 3,694 |
| 2024 | $325.0M | 4 | 6 | The Yellowstone Bank | 54.7% | 3,745 |
| 2023 | $325.4M | 4 | 6 | The Yellowstone Bank | 50.0% | 3,367 |
| 2022 | $374.2M | 4 | 6 | The Yellowstone Bank | 45.5% | 3,095 |
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.