---
schema_version: "secwatch.filing_event.v1"
accession: "0000950103-22-001727"
form_type: "8-K"
ticker: "FIBK"
cik: "0000860413"
company_name: "FIRST INTERSTATE BANCSYSTEM INC"
filed_at: "2022-02-01T23:59:59+00:00"
generated_at: "2026-06-27T13:16:34.877253+00:00"
event_type: "m_and_a"
sentiment: "positive"
materiality_score: 0.9
calibrated_materiality_score: 0.9
confidence: "high"
source: SEC EDGAR
---

# First Interstate completes $2.0B merger with Great Western; 0.8425 exchange ratio

## Summary
- Total aggregate consideration ~47M shares of FIBK Class A common stock; implied total value ~$2.0B.
- Five Great Western directors join FIBK board: Brannen, Grieb, Henning, Lacy, Rykhus; five GWB executives depart.
- FIBK assumes $83.8M in trust preferred securities and $35M subordinated notes; plans to redeem 2025 notes.
- Authorized shares of Class A common stock increased from 100M to 150M; bank systems conversion expected May 2022.
- Financial statements to be filed by amendment within 71 days; GWB delisted from NYSE.

## SEC filing metadata
- accession: 0000950103-22-001727
- form_type: 8-K
- ticker: FIBK
- cik: 0000860413
- company_name: FIRST INTERSTATE BANCSYSTEM INC
- filed_at: 2022-02-01T23:59:59+00:00
- event_type: m_and_a
- sentiment: positive
- materiality_score: 0.9
- calibrated_materiality_score: 0.9
- confidence: high
- sec_items: 2.01, 2.03, 5.02, 5.03, 7.01, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/860413/000095010322001727/0000950103-22-001727-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/860413/000095010322001727/dp16234_8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0000950103-22-001727
- JSON: https://secwatch.observer/filing/0000950103-22-001727.json
- Plain text: https://secwatch.observer/filing/0000950103-22-001727.txt

## Key facts
- Executive change
  Stephen Lacy was appointed as Director at FIRST INTERSTATE BANCSYSTEM INC.
  - Action: appointed
  - Role: Director
  source text: The five directors designated by Great Western pursuant to the Merger Agreement, each of whom previously served as a member of the board of directors of Great Western immediately prior to the Merger and was appointed by the Board to fill the vacancies resulting from the increase in the size of the Board referred to above, in each case effective as of the Effective Time, are as follows: James Brannen, Frances Grieb, Thomas Henning, Stephen Lacy and Daniel Rykhus (collectively, the “New Directors”).
  evidence_url: https://www.sec.gov/Archives/edgar/data/860413/000095010322001727/0000950103-22-001727-index.htm
- Executive change
  Frances Grieb was appointed as Director at FIRST INTERSTATE BANCSYSTEM INC.
  - Action: appointed
  - Role: Director
  source text: The five directors designated by Great Western pursuant to the Merger Agreement, each of whom previously served as a member of the board of directors of Great Western immediately prior to the Merger and was appointed by the Board to fill the vacancies resulting from the increase in the size of the Board referred to above, in each case effective as of the Effective Time, are as follows: James Brannen, Frances Grieb, Thomas Henning, Stephen Lacy and Daniel Rykhus (collectively, the “New Directors”).
  evidence_url: https://www.sec.gov/Archives/edgar/data/860413/000095010322001727/0000950103-22-001727-index.htm
- Executive change
  Daniel Rykhus was appointed as Director at FIRST INTERSTATE BANCSYSTEM INC.
  - Action: appointed
  - Role: Director
  source text: The five directors designated by Great Western pursuant to the Merger Agreement, each of whom previously served as a member of the board of directors of Great Western immediately prior to the Merger and was appointed by the Board to fill the vacancies resulting from the increase in the size of the Board referred to above, in each case effective as of the Effective Time, are as follows: James Brannen, Frances Grieb, Thomas Henning, Stephen Lacy and Daniel Rykhus (collectively, the “New Directors”).
  evidence_url: https://www.sec.gov/Archives/edgar/data/860413/000095010322001727/0000950103-22-001727-index.htm
- Executive change
  James Brannen was appointed as Director at FIRST INTERSTATE BANCSYSTEM INC.
  - Action: appointed
  - Role: Director
  source text: The five directors designated by Great Western pursuant to the Merger Agreement, each of whom previously served as a member of the board of directors of Great Western immediately prior to the Merger and was appointed by the Board to fill the vacancies resulting from the increase in the size of the Board referred to above, in each case effective as of the Effective Time, are as follows: James Brannen, Frances Grieb, Thomas Henning, Stephen Lacy and Daniel Rykhus (collectively, the “New Directors”).
  evidence_url: https://www.sec.gov/Archives/edgar/data/860413/000095010322001727/0000950103-22-001727-index.htm
- Executive change
  Thomas Henning was appointed as Director at FIRST INTERSTATE BANCSYSTEM INC.
  - Action: appointed
  - Role: Director
  source text: The five directors designated by Great Western pursuant to the Merger Agreement, each of whom previously served as a member of the board of directors of Great Western immediately prior to the Merger and was appointed by the Board to fill the vacancies resulting from the increase in the size of the Board referred to above, in each case effective as of the Effective Time, are as follows: James Brannen, Frances Grieb, Thomas Henning, Stephen Lacy and Daniel Rykhus (collectively, the “New Directors”).
  evidence_url: https://www.sec.gov/Archives/edgar/data/860413/000095010322001727/0000950103-22-001727-index.htm

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.