---
schema_version: "secwatch.filing_event.v1"
accession: "0001104659-25-080276"
form_type: "8-K"
ticker: "BKH"
cik: "0001130464"
company_name: "BLACK HILLS CORP /SD/"
filed_at: "2025-08-19T23:59:59+00:00"
generated_at: "2026-05-17T11:21:47.126324+00:00"
event_type: "m_and_a"
sentiment: "neutral"
materiality_score: 0.9
calibrated_materiality_score: 0.9
confidence: "high"
source: SEC EDGAR
---

# Black Hills Corporation (BKH) enters into all-stock merger agreement with NorthWestern Energy Group

## Summary
- Brian B. Bird, formerly NorthWestern's CEO, will become CEO of combined company; Linden R. Evans will retire.
- NorthWestern shareholders will receive 0.98 shares of BKH common stock per share in the merger.
- NewCo will be headquartered in Rapid City, SD, with an 11-member board (6 from BKH, 5 from NorthWestern).
- Merger requires approvals from FERC and state commissions in MT, NE, SD, and possibly AR, with a $100M termination fee.
- Closing expected by August 18, 2026, with possible extensions to February 18, 2027 for regulatory approvals.

## SEC filing metadata
- accession: 0001104659-25-080276
- form_type: 8-K
- ticker: BKH
- cik: 0001130464
- company_name: BLACK HILLS CORP /SD/
- filed_at: 2025-08-19T23:59:59+00:00
- event_type: m_and_a
- sentiment: neutral
- materiality_score: 0.9
- calibrated_materiality_score: 0.9
- confidence: high
- sec_items: 1.01, 5.02, 5.03, 7.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1130464/000110465925080276/0001104659-25-080276-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1130464/000110465925080276/tm2523729d1_8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001104659-25-080276
- JSON: https://secwatch.observer/filing/0001104659-25-080276.json
- Plain text: https://secwatch.observer/filing/0001104659-25-080276.txt

## Key facts
- Governance Changes
  BLACK HILLS CORP /SD/: Removed director age limit, added exclusive forum provisions for corporate-law and Securities Act suits in Pennington County, South Dakota (effective 2025-08-18).
  - Change: bylaw amendment
  - Effective: 2025-08-18
  source text: On August 18, 2025, prior to the execution of the Merger Agreement, the Black Hills Board adopted an amendment to Black Hills’ bylaws (the “ Bylaw Amendment ”). The Bylaw Amendment removes the age limit for directors as previously provided in Section 3. A modified retirement age provision was added to Black Hills’ Corporate Governance Guidelines at the same time. The Bylaw Amendment also adds a new Article X, which provides that, unless Black Hills consents in writing to the selection of an alternative forum, the federal and state courts located in Pennington County, South Dakota shall be the sole and exclusive forum for certain specified corporate-law based suits involving Black Hills. The Bylaw Amendment also provides for federal district court to be the sole and exclusive forum for the resolution of complaints arising under the Securities Act of 1933.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1130464/000110465925080276/0001104659-25-080276-index.htm

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