Core Natural Resources, Inc.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-Q

(Mark One)

For the quarterly period ended September 30, 2026

OR

For the transition period from ______ to ______

Commission file number:001-38147

Core Natural Resources, Inc.

(Exact name of registrant as specified in its charter)

275 Technology Drive, Suite 101

Canonsburg, PA 15317-9565

(Address of principal executive offices) (Zip code)

Registrant’s telephone number, including area code:(724)416-8300

Former name, former address and former fiscal year, if changed since last report: Not Applicable

Securities registered pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes ☒ No ☐

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes ☒ No ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

Large accelerated filer ☒ Accelerated filer ☐ Non-accelerated filer ☐ Smaller reporting company☐ Emerging growth company☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes ☐ No☒

Core Natural Resources, Inc. had 48,696,355 shares of common stock, $0.01 par value, outstanding at October 30, 2026.

TABLE OF CONTENTS

Explanatory Note

On January 14, 2025, CONSOL Energy Inc., a Delaware corporation, completed its previously announced all-stock merger of equals transaction (the “Merger”) with Arch Resources, Inc., a Delaware corporation (“Arch”), pursuant to that certain Agreement and Plan of Merger, dated as of August 20, 2024 (the “Merger Agreement”), by and among CONSOL Energy Inc., Mountain Range Merger Sub Inc., a Delaware corporation and wholly-owned subsidiary of CONSOL Energy Inc. (“Merger Sub”), and Arch. Pursuant to the terms of the Merger Agreement, Merger Sub merged with and into Arch, with Arch continuing as the surviving corporation and as a wholly-owned subsidiary of the Company. Additionally, pursuant to the Merger Agreement, the Company was renamed “Core Natural Resources, Inc.” and began trading under the ticker symbol “CNR” on January 15, 2025.

The information set forth herein does not include the results of operations or cash flows of Arch prior to January 14, 2025. Accordingly, unless otherwise specifically noted, references herein to “Core Natural Resources,” “Core,” “we,” “our,” “us,” “our Company” and “the Company” refer only to Core Natural Resources, Inc. and its subsidiaries and do not include Arch and its subsidiaries prior to the Merger. See Note 2—Merger with Arch for further discussion of the unaudited pro forma information.

Important Definitions Referenced in this Quarterly Report on Form 10-Q

•“Core Natural Resources,” “Core,” “we,” “our,” “us,” “our Company” and “the Company” refer to Core Natural Resources, Inc. (formerly known as CONSOL Energy Inc. before the effective time of the Merger) and its subsidiaries;

•“Arch” refers to Arch Resources, Inc., a Delaware corporation and a wholly-owned subsidiary of the Company following the Merger;

•“Beckley” refers to the Company’s low-vol metallurgical coal mining complex located in Raleigh County, West Virginia;

•“Black Thunder” refers to one of the Company’s sub-bituminous thermal coal surface mining complexes located in Campbell County, Wyoming;

•“Coal Creek” refers to one of the Company’s sub-bituminous thermal coal surface mining complexes located in Campbell County, Wyoming;

•“Core Marine Terminal” refers to the Company’s terminal operations located in the Port of Baltimore, Maryland;

•“Dominion Terminal” refers to the Company’s terminal operations located in Newport News, Virginia operated by DTA;

•“DTA” refers to Dominion Terminal Associates LLP, a limited liability partnership, in which the Company owns a 35% interest;

•“former parent” refers to CNX Resources Corporation and its consolidated subsidiaries;

•“Itmann” refers to the Company’s low-vol metallurgical coal mining complex located in Wyoming County, West Virginia;

•“Leer” refers to the Company’s high-vol metallurgical coal mining complex located in Taylor County, West Virginia;

•“Leer South” refers to the Company’s high-vol metallurgical coal mining complex located in Barbour County, West Virginia;

•“Merger” refers to the Company’s all-stock merger of equals transaction with Arch that closed on January 14, 2025;

•“Merger Agreement” refers to the Agreement and Plan of Merger, dated as of August 20, 2024, by and among the Company, Merger Sub and Arch;

•“Mountain Laurel” refers to the Company’s high-vol metallurgical coal mining complex located in Logan County and Boone County, West Virginia;

•“Pennsylvania Mining Complex” or “PAMC” refers to the Company’s Bailey, Enlow Fork and Harvey high calorific value thermal coal mines, and the Central Preparation Plant serving those mines, located in southwestern Pennsylvania and northern West Virginia; and

•“West Elk” refers to the Company’s high calorific value thermal coal mining complex located in Gunnison County, Colorado.