SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Schedule 13D

Under the Securities Exchange Act of 1934

(Amendment No. 1)*

HALLADOR ENERGY COMPANY

(Name of Issuer)

Common Stock, par value $0.01 per share

(Title of Class of Securities)

406092205

(CUSIP Number)

Bryan H. Lawrence

Yorktown Energy Partners VIII, L.P.

410 Park Avenue

19th Floor

New York, New York 10022

(212) 515-2112

Copies to:

Ann Marie Cowdrey

Thompson & Knight LLP

One Arts Plaza

1722 Routh Street, Suite 1500

Dallas, Texas 75201-2533

(214) 969-1700

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

November 12, 2018

(Date of Event which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box.  ☐

Note. Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See § 240.13d-7 for other parties to whom copies are to be sent.

*The remainder of the cover page shall be filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

This Amendment No. 1 amends the Schedule 13D with respect to the common stock, par value $0.01 per share (the “Common Stock”), of Hallador Energy Company, a Colorado corporation formerly known as Hallador Petroleum Company (the “Company”), previously filed by Yorktown Energy Partners VIII, L.P., a Delaware limited partnership (“Yorktown”), Yorktown VIII Company LP, a Delaware limited partnership (“Yorktown Company”) and Yorktown VIII Associates LLC, a Delaware limited liability company (“Yorktown Associates”), with the SEC on September 25, 2009 (the “Schedule 13D”). Capitalized terms used herein without definition shall have the meanings given to such terms in the Schedule 13D.

Subparagraphs a and c of Item 5 in the Schedule 13D are amended and restated in their entirety by the following:

(a)    As of December 4, 2018, Yorktown, Yorktown Company and Yorktown Associates beneficially own 1,950,000 shares of Common Stock of the Company, representing 6.46% of the issued and outstanding shares of Common Stock of the Company. All calculations made herein are made in accordance with Rule 13d-3(d) of the Securities Exchange Act of 1934, as amended, and based on 30,176,990 shares of Common Stock of the Company issued and outstanding as of November 2, 2018, as set forth in the Company’s quarterly report on Form 10-Q for the quarter ended September 30, 2018, filed with the SEC on November 5, 2018.

(c)    On November 12, 2018, Yorktown distributed in-kind, on a pro rata basis and for no additional consideration, in accordance with its limited partnership agreement, an aggregate of 1,000,000 shares of Common Stock of the Company, to its limited and general partners (the “Distribution”). Upon the consummation of the Distribution by Yorktown, Yorktown Company distributed in-kind, on a pro rata basis and for no additional consideration, in accordance with its limited partnership agreement, all 15,000 shares of Common Stock of the Company received in the Distribution to its limited and general partners (the “Subsequent Distribution”). Upon the consummation of the Subsequent Distribution by Yorktown Company, Yorktown Associates distributed in-kind, on a pro rata basis and for no additional consideration, in accordance with its operating agreement, all 87 shares of Common Stock of the Company received in the Subsequent Distribution to its members.

SIGNATURES

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Date: December 4, 2018