AND SECURITY HOLDERS ARE URGED TO READ THE REGISTRATION STATEMENT, JOINT PROXY STATEMENT/PROSPECTUS AND ANY OTHER RELEVANT DOCUMENTS THAT MAY BE FILED WITH THE SEC, AS WELL AS ANY AMENDMENTS OR
SUPPLEMENTS TO THOSE DOCUMENTS, CAREFULLY AND IN THEIR ENTIRETY IF AND WHEN THEY BECOME AVAILABLE BECAUSE THEY CONTAIN OR WILL CONTAIN IMPORTANT INFORMATION ABOUT ARCH, CONSOL AND THE PROPOSED TRANSACTION.
Investors and security holders will be able to obtain free copies of the registration statement, preliminary joint proxy statement/prospectus and definitive
joint proxy statement/prospectus (if and when available) and other documents containing important information about Arch, CONSOL and the proposed transaction, once such documents are filed with the SEC through the website maintained by the SEC at
http://www.sec.gov. Copies of the registration statement and preliminary joint proxy statement/prospectus, definitive joint proxy statement/prospectus (if and when available) and other documents filed with the SEC by Arch may be obtained free of
charge on Archs website at https://investor.archrsc.com/sec-filings/ or, alternatively, by directing a request by mail to Archs Corporate Secretary at One City Place Drive, Suite 300, St. Louis,
Missouri, 63141. Copies of the registration statement, preliminary joint proxy statement/prospectus and definitive joint proxy statement/prospectus (if and when available) and other documents filed with the SEC by CONSOL may be obtained free of
charge on CONSOLs website at https://investors.consolenergy.com/sec-filings or, alternatively, by directing a request by mail to CONSOLs Corporate Secretary at 275 Technology Drive, Suite 101,
Canonsburg, Pennsylvania 15317.
Participants in the Solicitation
Arch, CONSOL and certain of their respective directors and executive officers may be deemed to be participants in the solicitation of proxies in respect of the
proposed transaction. Information about the directors and executive officers of Arch, including a description of their direct or indirect interests, by security holdings or otherwise, is set forth in Archs proxy statement for its 2024 Annual
Meeting of Stockholders, which was filed with the SEC on March 27, 2024, including under the headings Executive Compensation, Director Compensation, Equity Compensation Plan Information, and Security
Ownership of Directors and Executive Officers. To the extent holdings of Arch common stock by the directors and executive officers of Arch have changed from the amounts of Arch common stock held by such persons as reflected therein, such
changes have been or will be reflected on Initial Statements of Beneficial Ownership of Securities on Form 3 (Form 3), Statements of Changes in Beneficial Ownership on Form 4 (Form 4) or Annual Statements of Changes in
Beneficial Ownership of Securities on Form 5 (Form 5), in each case filed with the SEC, including: the Form 3 filed by George John Schuller on March 19, 2024; and the Forms 4 filed by Pamela Butcher on March 13, 2024,
March 18, 2024, June 17, 2024 and September 16, 2024, James Chapman on March 11, 2024, Paul Demzik on March 5, 2024, John Eaves on March 8, 2024, Patrick Kriegshauser on March 18, 2024, June 17, 2024 and
September 16, 2024, Holly Koeppel on March 18, 2024, June 17, 2024 and September 16, 2024, Richard Navarre on March 18, 2024, June 17, 2024 and September 16, 2024, George John Schuller on March 21, 2024,
Peifang Zhang on March 18, 2024, June 17, 2024 and September 16, 2024, John Ziegler on March 8, 2024, John T. Drexler on October 15, 2024, Rosemary L. Klein on October 15, 2024, Deck Slone on October 15, 2024 and
Matthew C. Giljum on October 15, 2024. Information about the directors and executive officers of CONSOL, including a description of their direct or indirect interests, by security holdings or otherwise, is set forth in CONSOLs proxy
statement for its 2024 Annual Meeting of Stockholders, which was filed with the SEC on April 1, 2024, including under the headings Board of Directors and Compensation Information, Executive Compensation Information and
Beneficial Ownership of Securities. To the extent holdings of CONSOL common stock by the directors and executive officers of CONSOL have changed from the amounts of CONSOL common stock held by such persons as reflected therein, such
changes have been or will be reflected on Forms 3, Forms 4 or Forms 5, in each case filed with the SEC, including: the Forms 4 filed by James Brock on May 24, 2024 and July 1, 2024, John Mills on May 9, 2024, Cassandra Chia-Wei Pan on May 9, 2024, Valli Perera on May 9, 2024, Joseph Platt on May 9, 2024 and John Rothka on March 8, 2024. Other information regarding the participants in the proxy solicitations and
a description of their direct and indirect interests, by security holdings or otherwise, will be contained in the registration statement and joint proxy statement/prospectus and other relevant materials to be filed with the SEC regarding the
proposed transaction when such materials become available. Investors and security holders should read the registration statement and joint proxy statement/prospectus carefully when it becomes available before making any voting or investment
decisions. You may obtain free copies of any of the documents referenced herein from Arch or CONSOL using the sources indicated above.