| Name | Relationship | Address | Signature | Signature date | CIK |
|---|---|---|---|---|---|
| MACHUCA LUIS | Director | C/O COLUMBIA BANKING SYSTEM, INC., PO BOX 2156, MS 3100, TACOMA | /s/ Lisa M. White, Attorney-in-fact | 16 May 2025 | 0001133099 |
| Type | Sym | Class | Transaction | Value $ | Shares | Change % | * Price $ | Shares After | Date | Ownership | Footnotes |
|---|---|---|---|---|---|---|---|---|---|---|---|
| transaction | COLB | Common Stock | Award | $0 | +3,382 | +15% | $0.000000 | 26,004 | 15 May 2025 | Direct |