Item 1. Security and Issuer.

This Schedule 13D relates to the common units representing limited partnership interests (“ Common Units ”), of Rhino Resource Partners LP, a Delaware limited partnership (the “ Partnership ”), whose principal executive offices are located at 424 Lewis Hargett Circle, Suite 250, Lexington, KY 40503.

Item 2. Identity and Background.

a) This statement is filed by Weston Energy LLC, a Delaware limited liability company (“ Weston ”), Yorktown Energy Partners XI, L.P., a Delaware limited partnership (“ Yorktown XI ”), Yorktown XI Company LP, a Delaware limited partnership (“ Yorktown XI Company ”), and Yorktown XI Associates LLC, a Delaware limited liability company (“ Yorktown XI Associates ” and together with Weston, Yorktown XI and Yorktown XI Company, the “ Reporting Persons ”).

b) The principal business address of each of the Reporting Persons is 410 Park Avenue, 19th Floor, New York, New York 10022.

c) The principal business of Weston is investing in equity securities of the Partnership. The principal business of Yorktown XI is investing in equity securities of energy companies. The principal business of Yorktown XI Company is managing Yorktown XI. The principal business of Yorktown XI Associates is managing Yorktown XI Company. Information regarding the executive officers, directors or other control persons of the Reporting Persons is set forth on Schedule 1 attached hereto, which Schedule is hereby incorporated by reference.

d) None of the Reporting Persons or the persons identified on Schedule 1 hereto has, during the last five years, been convicted in a criminal proceeding (excluding traffic violations or similar misdemeanors).

e) None of the Reporting Persons or the persons identified on Schedule 1 has, during the last five years, been a party to a civil proceeding of a judicial or administrative body of competent jurisdiction and as a result of such proceeding was or is subject to a judgment, decree or final order enjoining future violations of, or prohibiting or mandating activities subject to, federal or state securities laws or finding any violation with respect to such laws.

f) All of the persons identified on Schedule 1 are citizens of the United States of America.

Item 3. Source and Amount of Funds or Other Consideration.

On December 30, 2016, Weston acquired 1,300,000 Series A Preferred Units (each, a “ Preferred Unit ”) from the Partnership for $10.00 per Preferred Unit pursuant to that certain Series A Preferred Unit Purchase Agreement (the “ Preferred Purchase Agreement ”) by and among the Partnership, Weston, and Royal Energy Resources, Inc., a Delaware corporation (“ Royal Energy ”). The Preferred Units have the preferences, rights and obligations set forth in the Fourth Amended and Restated Agreement of Limited Partnership of the Partnership (the “ Partnership Agreement ”). In exchange for the Preferred Units, Weston paid cash of $11.0 million to the Partnership and assigned to the Partnership a $2.0 million note receivable from Royal Energy originally dated September 30, 2016. Such Preferred Units are convertible into a number of Common Units equal to the quotient (the “ Series A Conversion Ratio ”) of (i) the sum of $10.00 and any unpaid distributions in respect of such Preferred Unit divided by (ii) 75% of the volume-weighted average closing price of the Common Units for the preceding 90 trading days (the “ VWAP ”); provided however, that the VWAP will be capped at a minimum of $2.00 and a maximum of $10.00. On December 31, 2021, all outstanding Preferred Units will convert into common units at the then applicable Series A Conversion Ratio. The Preferred Units are entitled to vote on an as-converted basis with the Common Units.

The foregoing description of the Preferred Purchase Agreement does not purport to be complete and is qualified in its entirety by reference to the full text of the Preferred Purchase Agreement filed as Exhibit 10.2 to the Partnership’s Current Report on Form 8-K, filed with the Securities and Exchange Commission on January 6, 2017, and is incorporated herein by reference.

On January 27, 2017, Royal Energy conveyed to Weston 100,000 Preferred Units to partially satisfy Royal Energy’s obligations to Weston pursuant to a promissory note in the principal amount of $2,000,000 executed by Royal Energy in favor of Weston on December 30, 2016, the remainder of such obligation being satisfied by a cash payment.

Item 4. Purpose of Transaction.

The Reporting Persons acquired the securities described in this Schedule 13D for investment purposes and they intend to review their investments in the Partnership on a continuing basis. The Reporting Persons have no plans or proposals which relate to, or could result in, any of the matters referred to in paragraphs (a) through (j) inclusive of the instructions to Item 4 of Schedule 13D. The Reporting Persons may, at any time and from time to time, review or reconsider their position, change their purpose or formulate plans or proposals with respect thereto.

Item 5. Interest in Securities of the Issuer.

(a) Each of the Reporting Persons beneficially owns an aggregate of 3,938,600 Common Units which may be acquired upon the conversion of the Preferred Units, representing 23.0% of the outstanding Common Units (based on 12,905,799 total outstanding Common Units of the Partnership as of March 17, 2017, as reported in the Partnership’s Annual Report on Form 10-K filed with the SEC on March 24, 2017, plus 1,500,000 Preferred Units which are convertible into an estimated 4,219,928 Common Units at $3.55 per Common Unit (the applicable VWAP as of April 17, 2017), for a total of 17,125,727 Common Units outstanding). Each Reporting Person disclaims beneficial ownership of the reported Common Units except to the extent of such Reporting Person’s pecuniary interest therein, and this statement shall not be deemed an admission that such Reporting Person is the beneficial owner of the reported Common Units for the purposes of Section 13(d) of the Exchange Act or any other purpose.

(b) The Preferred Units are directly held by Weston. Yorktown XI is a member of Weston owning more than a majority of the membership interest in Weston and has the requisite voting power to cause Weston to take certain actions Yorktown XI Company is the sole general partner of Yorktown XI. Yorktown XI Associates is the sole general partner of Yorktown XI Company. Yorktown XI Associates has the sole power to cause Yorktown XI Company to cause Yorktown XI to cause Weston to vote or direct the vote or to dispose or direct the disposition of the shares owned by Weston.

(c) Except as otherwise described herein or in any exhibit filed hereunder, none of the Reporting Persons has effected any transaction in the Common Units during the past 60 days.

(d) Except as otherwise described herein, no person other than the Reporting Persons has the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, the shares of Common Stock reported on this Schedule 13D.

(e) Not applicable.

Item 6. Contracts, Arrangements, Understandings or Relationships With Respect to Securities of the Issuer.

The information provided or incorporated by reference in Item 3 is hereby incorporated by reference herein.

Item 7. Material to Be Filed as Exhibits.

SIGNATURE

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: April 25, 2017

Schedule 1

CONTROL PERSONS AND EXECUTIVE OFFICERS OF REPORTING PERSONS

The name, business address, present principal occupation or employment and the name, principal business and address of any corporation or other organization in which such employment is conducted, of each of the executive officers and other control persons of the Reporting Persons are set forth below: