# EDGAR Filing Document

**Accession Number:** 0001441236
**File Stem:** 0001441236-26-000019
**Filing Date:** 2026-3
**Character Count:** 2484
**Document Hash:** 1be575c978040aac42eac7bb944cab91
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001441236-26-000019.hdr.sgml**: 20260327

**ACCESSION NUMBER**: 0001441236-26-000019

**CONFORMED SUBMISSION TYPE**: DEFA14A

**PUBLIC DOCUMENT COUNT**: 3

**FILED AS OF DATE**: 20260327

**DATE AS OF CHANGE**: 20260327

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Clearwater Paper Corp
- **CENTRAL INDEX KEY:** 0001441236
- **STANDARD INDUSTRIAL CLASSIFICATION:** PAPERBOARD MILLS [2631]
- **ORGANIZATION NAME:** 04 Manufacturing
- **EIN:** 203594554
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** DEFA14A
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-34146
- **FILM NUMBER:** 26803624

**BUSINESS ADDRESS:**
- **STREET 1:** 601 WEST RIVERSIDE AVENUE
- **STREET 2:** SUITE 1100
- **CITY:** SPOKANE
- **STATE:** WA
- **ZIP:** 99201
- **BUSINESS PHONE:** 509.344.5900

**MAIL ADDRESS:**
- **STREET 1:** 601 WEST RIVERSIDE AVENUE
- **STREET 2:** SUITE 1100
- **CITY:** SPOKANE
- **STATE:** WA
- **ZIP:** 99201

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** Potlatch Forest Products CORP
- **DATE OF NAME CHANGE:** 20080728

**UNITED STATES**

**SECURITIES AND EXCHANGE COMMISSION**

**WASHINGTON, D.C. 20549**

___________________________________

**SCHEDULE 14A Information**

**Proxy Statement Pursuant to Section 14(a) of**

**the Securities Exchange Act of 1934**

**(Amendment No. ___)**

___________________________________

Filed by the Registrant ☒ &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

Filed by a Party other than the Registrant ☐

**CHECK THE APPROPRIATE BOX:**

☐ Preliminary Proxy Statement

☐ **Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2))**

☐ Definitive Proxy Statement

☒ Definitive Additional Materials

☐ Soliciting Material Pursuant to §240.14a-12

**CLEARWATER PAPER CORPORATION**

**(Name of Registrant as Specified In Its Charter)**

**(Name of Person(s) Filing Proxy Statement, if other than the Registrant)**

**PAYMENT OF FILING FEE (CHECK ALL BOXES THAT APPLY):**

☒ No fee required.

☐ Fee paid previously with preliminary materials.

☐ Fee computed on table in exhibit required by Item 25(b) per Exchange Act Rules 14a-6(i)(1) and 0-11

------

![a2026beneficialnnainitialn.jpg](a2026beneficialnnainitialn.jpg)

------

![a2026beneficialnnainitialna.jpg](a2026beneficialnnainitialna.jpg)

<br>