| # | Institution | Type | Branches | Deposits | Share |
|---|---|---|---|---|---|
| 1 | First Interstate Bank | Bank | 1 | $243.7M | 37.09% |
| 2 | Black Hills Federal Credit Union | Credit union | 1 | $100.6M* | 15.30% |
| 3 | First National Bank in Philip | Bank | 1 | $69.1M | 10.51% |
| 4 | Northern Hills Federal Credit Union | Credit union | 2 | $60.9M* | 9.27% |
| 5 | Pioneer Bank & Trust | Bank | 1 | $58.8M | 8.96% |
| 6 | Wells Fargo Bank, National Association | Bank | 1 | $53.0M | 8.07% |
| 7 | First National Bank | Bank | 1 | $36.4M | 5.54% |
| 8 | Sentinel Federal Credit Union | Credit union | 1 | $21.0M* | 3.20% |
| 9 | Dakota Plains Federal Credit Union | Credit union | 1 | $13.5M* | 2.06% |
* Credit-union deposits are estimated (June total shares spread evenly across branches).
| Year | Deposits | Institutions | Branches | Leader | Top share | HHI |
|---|---|---|---|---|---|---|
| 2025 | $657.1M | 9 | 10 | First Interstate Bank | 37.1% | 1,997 |
| 2024 | $609.4M | 9 | 10 | First Interstate Bank | 37.9% | 2,062 |
| 2023 | $651.3M | 9 | 10 | First Interstate Bank | 34.9% | 1,946 |
| 2022 | $663.3M | 9 | 10 | First Interstate Bank | 34.6% | 1,944 |
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.