425

Filed by Weyerhaeuser Company

Pursuant to Rule 425 under the Securities Act of 1933

and deemed filed pursuant to Rule 14a-12

under the Securities Exchange Act of 1934

Subject Company: Plum Creek Timber Company, Inc.

Commission File No.: 001-10239

The following email was sent to the Weyerhaeuser employees by the Chief Executive Officer of Weyerhaeuser, Doyle Simons, on November 8, 2015:

DOYLE EMAIL TO EMPLOYEES

Today we made two significant announcements that will transform our company:

We have agreed to merge with Plum Creek, creating the world’s premier timber, land and forest products company with more than 13 million acres of some of the most diverse and productive forests in the country. The combined company will retain the Weyerhaeuser name. This is an exciting step forward to grow our company, drive shareholder value, and create a winning organization with a shared focus on achieving excellence.

At the same time, we announced that we are going to explore strategic alternatives for our Cellulose Fibers business. This was a very difficult decision to make, but I believe it is the right decision not only for our shareholders, but also for our talented and dedicated CF employees who deserve to be part of a company that is focused on investing in their future growth.

On Monday morning we will hold two conference calls that I encourage you to attend if you can.

Analyst/Investor Conference Call: At 5:30 a.m. Pacific Time, Nov. 9, we will host a webcast with analysts and investors. If you can’t join live, the recording and presentation will be archived at www.wy.com shortly after the call concludes.

Employee Conference Call: At 9:00 a.m. Pacific Time, Nov. 9, I will hold a conference call for all employees to talk more about these announcements, including what to expect in the months ahead.

I know this news will generate lots of questions and uncertainty. On Roots you’ll find more information and initial Q&A documents with answers we know today. While there are legal limitations on what we can say during the transition period for both these announcements, we are committed to collecting your questions and providing as many answers as possible in the coming months.

Finally, I want to remind everyone that it’s distracting times like this when our safety value is really put to the test. Please watch out for each other and have the courage to intervene if you see an unsafe condition or behavior. Nothing we’ve announced today is more important than your personal safety and the safety of those around you.

Doyle

FORWARD-LOOKING STATEMENTS

This communication contains statements that are forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, including, without limitation, with respect to Weyerhaeuser’s future results and performance, the expected benefits of the proposed transaction such as efficiencies, cost savings and growth potential and the expected timing of the completion of the transaction, all of which are subject to risks and uncertainties. Factors listed below, as well as other factors, may cause actual results to differ significantly from these forward-looking statements. There is no guarantee that any of the events anticipated by these forward-looking statements will occur. If any of the events occur, there is no guarantee what effect they will have on our operations or financial condition. Weyerhaeuser will not update these forward-looking statements after the date of this communication.


Some forward-looking statements discuss Weyerhaeuser’s and Plum Creek’s plans, strategies, expectations and intentions. They use words such as “expects,” “may,” “will,” “believes,” “should,” “approximately,” “anticipates,” “estimates,” and “plans.” In addition, these words may use the positive or negative or other variations of those and similar words.

Major risks, uncertainties and assumptions that affect Weyerhaeuser’s and Plum Creek’s businesses and may cause actual results to differ materially from those expressed or implied in these forward-looking statements, including, without limitation, the failure to receive, on a timely basis or otherwise, the required approval of Weyerhaeuser’s shareholders or Plum Creek’s stockholders with respect to the proposed transaction; the risk that any of the conditions to closing of the proposed transaction may not be satisfied; the risk that the businesses of Weyerhaeuser and Plum Creek will not be integrated successfully; the effect of general economic conditions, including employment rates, housing starts, interest rate levels, availability of financing for home mortgages, and strength of the U.S. dollar; market demand for our products, which is related to the strength of the various U.S. business segments and U.S. and international economic conditions; performance of our manufacturing operations, including maintenance requirements; the level of competition from domestic and foreign producers; the successful execution of internal performance plans, including restructurings and cost reduction initiatives; raw material prices; energy prices; the effect of weather; the risk of loss from fires, floods, windstorms, hurricanes, pest infestation and other natural disasters; transportation availability and costs; federal tax policies; the effect of forestry, land use, environmental and other governmental regulations; legal proceedings; performance of pension fund investments and related derivatives; the effect of timing of retirements and changes in the market price of company stock on charges for stock-based compensation; changes in accounting principles; and other factors described in Weyerhaeuser’s and Plum Creek’s filings with the SEC, including the “Risk Factors” section in Weyerhaeuser’s and Plum Creek’s respective annual reports on Form 10-K for the year ended December 31, 2014.

NO OFFER OR SOLICITATION

This communication is neither an offer to purchase, nor a solicitation of an offer to sell, subscribe for or buy any securities or the solicitation of any vote or approval in any jurisdiction pursuant to or in connection with the proposed transaction or otherwise, nor shall there be any sale, issuance or transfer of securities in any jurisdiction in contravention of applicable law.

ADDITIONAL INFORMATION AND WHERE TO FIND IT

The proposed transaction involving Weyerhaeuser and Plum Creek will be submitted to Weyerhaeuser’s shareholders and Plum Creek’s stockholders for their consideration. In connection with the proposed transaction, Weyerhaeuser intends to file with the SEC a registration statement on Form S-4 (the “Registration Statement”), which will include a prospectus with respect to Weyerhaeuser’s common shares to be issued in the proposed transaction and a joint proxy statement for Weyerhaeuser’s shareholders and Plum Creek’s stockholders (the “Joint Proxy Statement”) and each of Weyerhaeuser and Plum Creek will mail the Joint Proxy Statement to their respective shareholders or stockholders, as applicable, and file other documents regarding the proposed transaction with the SEC. SECURITY HOLDERS ARE URGED AND ADVISED TO READ ALL RELEVANT MATERIALS FILED WITH THE SEC, INCLUDING THE REGISTRATION STATEMENT AND THE JOINT PROXY STATEMENT, CAREFULLY WHEN THEY BECOME AVAILABLE BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION ABOUT THE PROPOSED TRANSACTION AND RELATED MATTERS. The Registration Statement, the Joint Proxy Statement and other relevant materials (when they become available) and any other documents filed or furnished by Weyerhaeuser or Plum Creek with the SEC may be obtained free of charge at the SEC’s web site at www.sec.gov. In addition, security holders will be able to obtain free copies of the Registration Statement and the Joint Proxy Statement from Weyerhaeuser upon written request to Weyerhaeuser Company, 33663 Weyerhaeuser Way South, Federal Way, Washington 98003, Attention: Director, Investor Relations, or by calling (253) 924-2058, or from Plum Creek upon written request to Plum Creek, 601 Union Street, Suite 3100, Seattle Washington 98101, Attention: Investor Relations, or by calling (800) 858-5347.

PARTICIPANTS IN THE SOLICITATION

Weyerhaeuser, Plum Creek, their respective directors and certain of their respective executive officers and employees may be deemed to be participants in the solicitation of proxies in connection with the proposed transaction. Information about Weyerhaeuser’s directors and executive officers is set forth in its definitive proxy statement for its 2015 Annual Meeting of Shareholders, which was filed with the SEC on April 1, 2015, and information about Plum Creek’s directors and executive officers is set forth in its definitive proxy statement for its


2015 Annual Meeting of Stockholders, which was filed with the SEC on March 26, 2015. These documents are available free of charge from the sources indicated above, and from Weyerhaeuser by going to its investor relations page on its corporate web site at www.weyerhaeuser.com and from Plum Creek by going to its investor relations page on its corporate web site at www.plumcreek.com.

Additional information regarding the interests of participants in the solicitation of proxies in connection with the proposed transaction will be included in the Registration Statement, the Joint Proxy Statement and other relevant materials Weyerhaeuser and Plum Creek intend to file with the SEC.