Otter Tail Corp SEC filings OTTR
Otter Tail Corp has 878 filings in SEC EDGAR's recent list, going back to Jul 1, 2009. Its latest annual report, Form ARS, was filed on Mar 2, 2026 for the period ended Dec 31, 2025. The latest quarterly report (Form 10-Q) was filed on Nov 4, 2026, covering the quarter ended Sep 30, 2026. The most recent current report (Form 8-K) was filed on Nov 3, 2026 (results of operations). The company's fiscal year ends on December 31.
| Form | Description | Filed | Period |
|---|---|---|---|
| 10-Q | Quarterly report | Nov 4, 2026 | Sep 30, 2026 |
| 8-K |
Current report
Results of operations
|
Nov 3, 2026 | Nov 2, 2026 |
| 8-K |
Current report
Officer or director change
|
Sep 1, 2026 | Aug 28, 2026 |
| 4 | Insider transaction | Aug 12, 2026 | Aug 10, 2026 |
| 4 | Insider transaction | Aug 11, 2026 | Aug 7, 2026 |
| 144 | Notice of proposed sale | Aug 7, 2026 | — |
| SCHEDULE 13G | Ownership over 5% (passive) | Aug 7, 2026 | — |
| 10-Q | Quarterly report | Aug 5, 2026 | Jun 30, 2026 |
| 8-K |
Current report
Results of operations
|
Aug 4, 2026 | Aug 3, 2026 |
| 8-K |
Current report
Material agreement
|
Jun 18, 2026 | Jun 17, 2026 |
| 8-K |
Current report
New debt
|
Jun 5, 2026 | Jun 4, 2026 |
| SD | Specialized disclosure (conflict minerals) | May 29, 2026 | — |
| 8-K |
Current report
Material agreement
|
May 29, 2026 | May 28, 2026 |
| 8-K |
Current report
Other events
|
May 15, 2026 | May 15, 2026 |
| 10-Q | Quarterly report | May 6, 2026 | Mar 31, 2026 |
| 8-K |
Current report
Results of operations
|
May 5, 2026 | May 4, 2026 |
| SCHEDULE 13G | Ownership over 5% (passive) | Apr 30, 2026 | — |
| SCHEDULE 13G | Ownership over 5% (passive) | Apr 29, 2026 | — |
| 4 | Insider transaction | Apr 15, 2026 | Apr 13, 2026 |
| 4 | Insider transaction | Apr 15, 2026 | Apr 13, 2026 |
| 4 | Insider transaction | Apr 15, 2026 | Apr 13, 2026 |
| 4 | Insider transaction | Apr 15, 2026 | Apr 13, 2026 |
| 8-K |
Current report
Shareholder vote results
|
Apr 15, 2026 | Apr 13, 2026 |
| 3 | Initial insider ownership | Apr 14, 2026 | Apr 13, 2026 |
| 4 | Insider transaction | Apr 14, 2026 | Apr 13, 2026 |
| 4 | Insider transaction | Apr 14, 2026 | Apr 13, 2026 |
| 8-K |
Current report
Officer or director change, Regulation FD disclosure
|
Apr 14, 2026 | Apr 13, 2026 |
| 4 | Insider transaction | Apr 14, 2026 | Apr 13, 2026 |
| 4 | Insider transaction | Apr 14, 2026 | Apr 13, 2026 |
| 4 | Insider transaction | Apr 14, 2026 | Apr 13, 2026 |
| 4 | Insider transaction | Apr 14, 2026 | Apr 13, 2026 |
| 4 | Insider transaction | Apr 14, 2026 | Apr 13, 2026 |
| 4 | Insider transaction | Apr 14, 2026 | Apr 13, 2026 |
| 4 | Insider transaction | Apr 14, 2026 | Apr 13, 2026 |
| 4 | Insider transaction | Apr 9, 2026 | Apr 8, 2026 |
| SCHEDULE 13G/A | Amended ownership over 5% (passive) | Mar 27, 2026 | — |
| 8-K |
Current report
Material agreement, New debt
|
Mar 23, 2026 | Mar 19, 2026 |
| ARS | Annual report to shareholders | Mar 2, 2026 | Dec 31, 2025 |
| DEFA14A | Additional proxy material | Mar 2, 2026 | — |
| DEF 14A | Proxy statement | Mar 2, 2026 | Apr 13, 2026 |
| 10-K/A | Amended annual report | Feb 23, 2026 | Dec 31, 2025 |
| PRE 14A | Preliminary proxy statement | Feb 18, 2026 | Apr 13, 2026 |
| 10-K | Annual report | Feb 18, 2026 | Dec 31, 2025 |
| 8-K |
Current report
Results of operations
|
Feb 17, 2026 | Feb 16, 2026 |
| 4 | Insider transaction | Feb 12, 2026 | Feb 10, 2026 |
| 4 | Insider transaction | Feb 12, 2026 | Feb 10, 2026 |
| 4 | Insider transaction | Feb 12, 2026 | Feb 10, 2026 |
| 4 | Insider transaction | Feb 12, 2026 | Feb 10, 2026 |
| 4 | Insider transaction | Feb 12, 2026 | Feb 10, 2026 |
| 4 | Insider transaction | Feb 12, 2026 | Feb 10, 2026 |
| 4 | Insider transaction | Feb 9, 2026 | Feb 6, 2026 |
| 4 | Insider transaction | Feb 9, 2026 | Feb 6, 2026 |
| 4 | Insider transaction | Feb 9, 2026 | Feb 6, 2026 |
| 4 | Insider transaction | Feb 9, 2026 | Feb 6, 2026 |
| 4 | Insider transaction | Feb 9, 2026 | Feb 6, 2026 |
| 4 | Insider transaction | Feb 9, 2026 | Feb 6, 2026 |
| 3 | Initial insider ownership | Jan 6, 2026 | Jan 1, 2026 |
| 3 | Initial insider ownership | Jan 6, 2026 | Jan 1, 2026 |
| 8-K |
Current report
Officer or director change, Regulation FD disclosure
|
Dec 18, 2025 | Dec 16, 2025 |
| 10-Q | Quarterly report | Nov 5, 2025 | Sep 30, 2025 |
| 8-K |
Current report
Results of operations
|
Nov 4, 2025 | Nov 3, 2025 |
| 10-Q | Quarterly report | Aug 6, 2025 | Jun 30, 2025 |
| 8-K |
Current report
Results of operations
|
Aug 5, 2025 | Aug 4, 2025 |
| 8-K |
Current report
New debt
|
Jun 6, 2025 | Jun 5, 2025 |
| 8-K |
Current report
Other events
|
Jun 5, 2025 | Jun 4, 2025 |
| SD | Specialized disclosure (conflict minerals) | May 30, 2025 | — |
| 10-Q | Quarterly report | May 7, 2025 | Mar 31, 2025 |
| 8-K |
Current report
Results of operations
|
May 6, 2025 | May 5, 2025 |
| 8-K |
Current report
Shareholder vote results
|
Apr 17, 2025 | Apr 14, 2025 |
| 4 | Insider transaction | Apr 14, 2025 | Apr 13, 2025 |
| 4 | Insider transaction | Apr 14, 2025 | Apr 13, 2025 |
| 4 | Insider transaction | Apr 14, 2025 | Apr 13, 2025 |
| 4 | Insider transaction | Apr 14, 2025 | Apr 13, 2025 |
| 4 | Insider transaction | Apr 14, 2025 | Apr 13, 2025 |
| 4 | Insider transaction | Apr 14, 2025 | Apr 13, 2025 |
| 4 | Insider transaction | Apr 14, 2025 | Apr 13, 2025 |
| 4 | Insider transaction | Apr 14, 2025 | Apr 13, 2025 |
| 4 | Insider transaction | Apr 9, 2025 | Apr 8, 2025 |
| 8-K |
Current report
Material agreement, New debt
|
Mar 31, 2025 | Mar 27, 2025 |
| ARS | Annual report to shareholders | Mar 3, 2025 | Dec 31, 2024 |
| DEF 14A | Proxy statement | Mar 3, 2025 | Dec 31, 2024 |
| DEFA14A | Additional proxy material | Mar 3, 2025 | — |
| 10-K | Annual report | Feb 19, 2025 | Dec 31, 2024 |
| 8-K |
Current report
Results of operations
|
Feb 18, 2025 | Feb 17, 2025 |
| 4 | Insider transaction | Feb 13, 2025 | Feb 11, 2025 |
| 4 | Insider transaction | Feb 13, 2025 | Feb 11, 2025 |
| 4 | Insider transaction | Feb 13, 2025 | Feb 11, 2025 |
| 4 | Insider transaction | Feb 13, 2025 | Feb 11, 2025 |
| 4 | Insider transaction | Feb 13, 2025 | Feb 11, 2025 |
| 4 | Insider transaction | Feb 13, 2025 | Feb 11, 2025 |
| 4 | Insider transaction | Feb 7, 2025 | Feb 6, 2025 |
| 4 | Insider transaction | Feb 7, 2025 | Feb 6, 2025 |
| 4 | Insider transaction | Feb 7, 2025 | Feb 6, 2025 |
| 4 | Insider transaction | Feb 7, 2025 | Feb 6, 2025 |
| 4 | Insider transaction | Feb 7, 2025 | Feb 6, 2025 |
| 4 | Insider transaction | Feb 7, 2025 | Feb 6, 2025 |
| 8-K |
Current report
Other events
|
Dec 31, 2024 | Dec 30, 2024 |
| 8-K |
Current report
Material agreement, New debt
|
Dec 16, 2024 | Dec 11, 2024 |
| 10-Q | Quarterly report | Nov 7, 2024 | Sep 30, 2024 |
| 8-K |
Current report
Results of operations
|
Nov 5, 2024 | Nov 4, 2024 |
| SC 13D/A | Amended ownership over 5% (active) | Oct 3, 2024 | — |
| 4 | Insider transaction | Aug 14, 2024 | Aug 13, 2024 |
| 144 | Notice of proposed sale | Aug 13, 2024 | — |
| 10-Q | Quarterly report | Aug 7, 2024 | Jun 30, 2024 |
| 8-K |
Current report
Results of operations
|
Aug 6, 2024 | Aug 5, 2024 |
| 8-K |
Current report
Other events
|
Jun 5, 2024 | May 30, 2024 |
| 4 | Insider transaction | May 28, 2024 | May 24, 2024 |
| SD | Specialized disclosure (conflict minerals) | May 24, 2024 | — |
| 144 | Notice of proposed sale | May 24, 2024 | — |
| 10-Q | Quarterly report | May 8, 2024 | Mar 31, 2024 |
| 8-K |
Current report
Results of operations
|
May 7, 2024 | May 6, 2024 |
| S-3ASR | Automatic shelf registration | May 3, 2024 | — |
| S-3ASR | Automatic shelf registration | May 3, 2024 | — |
| 8-K |
Current report
Shareholder vote results
|
Apr 10, 2024 | Apr 8, 2024 |
| 4 | Insider transaction | Apr 9, 2024 | Apr 8, 2024 |
| 4 | Insider transaction | Apr 9, 2024 | Apr 8, 2024 |
| 4 | Insider transaction | Apr 9, 2024 | Apr 8, 2024 |
| 4 | Insider transaction | Apr 9, 2024 | Apr 8, 2024 |
| 4 | Insider transaction | Apr 9, 2024 | Apr 8, 2024 |
| 4 | Insider transaction | Apr 9, 2024 | Apr 8, 2024 |
| 4 | Insider transaction | Apr 9, 2024 | Apr 8, 2024 |
| 4 | Insider transaction | Apr 9, 2024 | Apr 8, 2024 |
| 4 | Insider transaction | Apr 9, 2024 | Apr 8, 2024 |
| 8-K |
Current report
Other events
|
Apr 5, 2024 | Apr 2, 2024 |
| 8-K |
Current report
Material agreement, New debt
|
Apr 2, 2024 | Mar 28, 2024 |
| 4 | Insider transaction | Mar 13, 2024 | Mar 12, 2024 |
| DEFA14A | Additional proxy material | Feb 28, 2024 | — |
| DEF 14A | Proxy statement | Feb 28, 2024 | Dec 31, 2023 |
| ARS | Annual report to shareholders | Feb 28, 2024 | Dec 31, 2023 |
| 10-K | Annual report | Feb 14, 2024 | Dec 31, 2023 |
| SC 13G/A | Amended ownership over 5% (passive) | Feb 13, 2024 | — |
| 8-K |
Current report
Results of operations
|
Feb 13, 2024 | Feb 12, 2024 |
| 4 | Insider transaction | Feb 8, 2024 | Feb 6, 2024 |
| 4 | Insider transaction | Feb 8, 2024 | Feb 6, 2024 |
| 4 | Insider transaction | Feb 8, 2024 | Feb 6, 2024 |
| 4 | Insider transaction | Feb 8, 2024 | Feb 6, 2024 |
| 4 | Insider transaction | Feb 8, 2024 | Feb 6, 2024 |
| 4 | Insider transaction | Feb 8, 2024 | Feb 6, 2024 |
| 8-K |
Current report
Officer or director change
|
Jan 29, 2024 | Jan 26, 2024 |
| 5 | Annual insider ownership | Jan 23, 2024 | Dec 31, 2023 |
| 5 | Annual insider ownership | Jan 23, 2024 | Dec 31, 2023 |
| SC 13G/A | Amended ownership over 5% (passive) | Jan 22, 2024 | — |
| 3 | Initial insider ownership | Jan 8, 2024 | Jan 1, 2024 |
| 4 | Insider transaction | Jan 2, 2024 | Dec 31, 2023 |
| 8-K |
Current report
Other events
|
Dec 21, 2023 | Dec 15, 2023 |
| 4 | Insider transaction | Nov 20, 2023 | Nov 20, 2023 |
| 144 | Notice of proposed sale | Nov 20, 2023 | — |
| 10-Q | Quarterly report | Nov 3, 2023 | Sep 30, 2023 |
| 8-K |
Current report
Results of operations
|
Oct 31, 2023 | Oct 30, 2023 |
| 8-K |
Current report
Officer or director change
|
Oct 4, 2023 | Oct 2, 2023 |
| 10-Q | Quarterly report | Aug 2, 2023 | Jun 30, 2023 |
| 8-K |
Current report
Results of operations
|
Aug 1, 2023 | Jul 31, 2023 |
| 8-K/A |
Amended current report
Shareholder vote results
|
Jun 20, 2023 | Apr 16, 2023 |
| SD | Specialized disclosure (conflict minerals) | May 25, 2023 | — |
| 10-Q | Quarterly report | May 3, 2023 | Mar 31, 2023 |
| 8-K |
Current report
Results of operations
|
May 2, 2023 | May 1, 2023 |
| 8-K |
Current report
Officer or director change, Shareholder vote results
|
Apr 19, 2023 | Apr 16, 2023 |
| 4 | Insider transaction | Apr 19, 2023 | Apr 17, 2023 |
| 4 | Insider transaction | Apr 19, 2023 | Apr 17, 2023 |
| 4 | Insider transaction | Apr 19, 2023 | Apr 17, 2023 |
| 4 | Insider transaction | Apr 19, 2023 | Apr 17, 2023 |
| 4 | Insider transaction | Apr 19, 2023 | Apr 17, 2023 |
| 4 | Insider transaction | Apr 19, 2023 | Apr 17, 2023 |
| 4 | Insider transaction | Apr 19, 2023 | Apr 17, 2023 |
| 4 | Insider transaction | Apr 19, 2023 | Apr 17, 2023 |
| 4 | Insider transaction | Apr 19, 2023 | Apr 17, 2023 |
| S-8 | Employee stock plan registration | Apr 17, 2023 | — |
| 8-K |
Current report
Other events
|
Mar 31, 2023 | Mar 31, 2023 |
| SC 13G/A | Amended ownership over 5% (passive) | Mar 8, 2023 | — |
| DEFA14A | Additional proxy material | Mar 7, 2023 | — |
| DEFR14A | Filing | Mar 7, 2023 | — |
| DEF 14A | Proxy statement | Mar 1, 2023 | — |
| ARS | Annual report to shareholders | Mar 1, 2023 | Dec 31, 2022 |
| 10-K | Annual report | Feb 15, 2023 | Dec 31, 2022 |
| 8-K |
Current report
Results of operations
|
Feb 14, 2023 | Feb 13, 2023 |
| 4 | Insider transaction | Feb 9, 2023 | Feb 7, 2023 |
| 4 | Insider transaction | Feb 9, 2023 | Feb 7, 2023 |
| 4 | Insider transaction | Feb 9, 2023 | Feb 7, 2023 |
| 4 | Insider transaction | Feb 9, 2023 | Feb 7, 2023 |
| 4 | Insider transaction | Feb 9, 2023 | Feb 7, 2023 |
| 4 | Insider transaction | Feb 9, 2023 | Feb 7, 2023 |
| SC 13G/A | Amended ownership over 5% (passive) | Feb 9, 2023 | — |
| 4 | Insider transaction | Feb 8, 2023 | Feb 6, 2023 |
| 4 | Insider transaction | Feb 8, 2023 | Feb 6, 2023 |
| 4 | Insider transaction | Feb 8, 2023 | Feb 6, 2023 |
| 4 | Insider transaction | Feb 8, 2023 | Feb 6, 2023 |
| 4 | Insider transaction | Feb 8, 2023 | Feb 6, 2023 |
| 4 | Insider transaction | Feb 8, 2023 | Feb 6, 2023 |
| SC 13G/A | Amended ownership over 5% (passive) | Jan 31, 2023 | — |
| 5 | Annual insider ownership | Jan 24, 2023 | Dec 31, 2022 |
| 3 | Initial insider ownership | Jan 10, 2023 | Jan 1, 2023 |
| 3 | Initial insider ownership | Jan 10, 2023 | Jan 1, 2023 |
| 4 | Insider transaction | Jan 3, 2023 | Dec 31, 2022 |
| 8-K |
Current report
Officer or director change
|
Dec 22, 2022 | Dec 21, 2022 |
| 4 | Insider transaction | Nov 22, 2022 | Nov 21, 2022 |
| 10-Q | Quarterly report | Nov 2, 2022 | Sep 30, 2022 |
| 8-K |
Current report
Material agreement, Results of operations, New debt
|
Nov 1, 2022 | Oct 31, 2022 |
| 8-K |
Current report
Other events
|
Oct 19, 2022 | Oct 14, 2022 |
| 4 | Insider transaction | Oct 3, 2022 | Sep 30, 2022 |
| 8-K |
Current report
Officer or director change
|
Sep 23, 2022 | Sep 21, 2022 |
Showing 200 filings, the most recent 200. Main filings leave out insider and ownership forms such as Form 4; choose a type above to see them. Each form opens on SEC.gov. Older filings are on SEC EDGAR.
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Company profile
- Industry
- Electric Services (SIC 4911)
- Listed as
- OTTR (Nasdaq)
- Fiscal year ends
- December 31
- Incorporated in
- MN
- Headquarters
- Fergus Falls, MN
- SEC filer status
- Large accelerated filer
- SEC CIK
- 1466593
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Source: SEC EDGAR filings. This is company-reported data, not investment advice.