SCHEDULE 13D

(Rule 13d-101)

INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO RULE 13d-1(a) AND AMENDMENTS THERETO FILED PURSUANT TO RULE 13d-2(a)

Under the Securities Exchange Act of 1934 (Amendment No. 6)*

(Name of Issuer)

(Title of Class of Securities)

(CUSIP Number)

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

(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. o

Note: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See Rule 13d-7 for other parties to whom copies are to be sent.

* The remainder of this 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).

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The Schedule 13D filed on December 8, 2014 by TRT Holdings, Inc. (“TRT Holdings”), Cresta Investments, LLC (“Cresta Investments”), Cresta Greenwood, LLC (“Cresta Greenwood”) and Robert B. Rowling (“Mr. Rowling” and, collectively with TRT Holdings, Cresta Investments and Cresta Greenwood, the “Reporting Persons”) relating to the common stock, par value $0.001 per share (the “Common Shares”), of Northern Oil and Gas, Inc., a Minnesota corporation (the “Issuer”), as amended by Amendment No. 1 filed on January 5, 2015, Amendment No. 2 filed on December 11, 2015, Amendment No. 3 filed on January 15, 2016, Amendment No. 4 filed on January 22, 2016 and Amendment No. 5 filed on February 5, 2016 (the “Schedule 13D”), is hereby amended and supplemented as set forth below by this Amendment No. 6 to the Schedule 13D.

Item 3.                       Source and Amount of Funds or Other Consideration

Item 3 of the Schedule 13D is hereby amended and supplemented with the following:

From February 5, 2016 through the close of business on February 12, 2016, TRT Holdings acquired 866,611 Common Shares for an aggregate purchase price of $2,487,325.82, which includes commissions, utilizing the working capital of TRT Holdings.  All Common Shares acquired by TRT Holdings have been acquired on the New York Stock Exchange.

Item 5.                                 Interest in Securities of the Issuer

Item 5 of the Schedule 13D is hereby amended and supplemented with the following:

(a)                                               At the close of business on February 12, 2016, the Reporting Persons beneficially owned, in the aggregate, 11,332,066 Common Shares, which constitute approximately 18.00% of the class outstanding, of which (i) TRT Holdings beneficially owned the 6,039,922 Common Shares held directly by TRT Holdings, which constitute approximately 9.59% of the class outstanding, (ii) Cresta Investments beneficially owned the 3,947,921 Common Shares held directly by Cresta Investments, which constitute approximately 6.27% of the class outstanding, (iii) Cresta Greenwood beneficially owned the 1,344,223 Common Shares held directly by Cresta Greenwood, which constitute approximately 2.14% of the class outstanding, and (iv) Mr. Rowling beneficially owned all of the 11,332,066 Common Shares held directly by TRT Holdings, Cresta Investments and Cresta Greenwood, which constitute approximately 18.00% of the class outstanding (in each case, based upon 62,960,639 Common Shares outstanding at October 31, 2015, according to the Issuer’s Quarterly Report on Form 10-Q filed on November 5, 2015). Mr. Rowling beneficially owns the Common Shares held directly by TRT Holdings due to his ownership of all of the shares of Class B Common Stock of TRT Holdings. Mr. Rowling beneficially owns the Common Shares held directly by Cresta Investments and Cresta Greenwood due to his direct and indirect ownership of 100% of the ownership interests in such entities.

(b)                                               Each of the Reporting Persons, either directly or indirectly, has the power to vote or to direct the vote and to dispose or to direct the disposition of the shares of Common Stock reported as beneficially owned by them in Item 5(a).

(c)                                                The table below specifies the date, amount and price of the Common Shares purchased by the Reporting Persons since the Reporting Persons’ most recent filing of Amendment No. 5 filed on February 5, 2016.  All transactions reflected in the table below were effected in the open market on the New York Stock Exchange.

(1) The price reported for the Common Shares purchased by TRT Holdings on February 5, 2016 is the weighted average price. The Common Shares were purchased in multiple transactions at prices ranging from $3.0600 to $3.2500, inclusive. The Reporting Persons undertake to provide, upon request by the Staff of the Securities and Exchange Commission, full information regarding the number of

Common Shares purchased at each separate price within the ranges set forth in this footnote.

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(2) The price reported for the Common Shares purchased by TRT Holdings on February 8, 2016 is the weighted average price. The Common Shares were purchased in multiple transactions at prices ranging from $2.7650 to $2.9000, inclusive. The Reporting Persons undertake to provide, upon request by the Staff of the Securities and Exchange Commission, full information regarding the number of Common Shares purchased at each separate price within the ranges set forth in this footnote.

(3) The price reported for the Common Shares purchased by TRT Holdings on February 9, 2016 is the weighted average price. The Common Shares were purchased in multiple transactions at prices ranging from $2.5200 to $2.6800, inclusive. The Reporting Persons undertake to provide, upon request by the Staff of the Securities and Exchange Commission, full information regarding the number of Common Shares purchased at each separate price within the ranges set forth in this footnote.

(4) The price reported for the Common Shares purchased by TRT Holdings on February 10, 2016 is the weighted average price. The Common Shares were purchased in multiple transactions at prices ranging from $2.5750 to $2.9300, inclusive. The Reporting Persons undertake to provide, upon request by the Staff of the Securities and Exchange Commission, full information regarding the number of Common Shares purchased at each separate price within the ranges set forth in this footnote.

(5) The price reported for the Common Shares purchased by TRT Holdings on February 11, 2016 is the weighted average price. The Common Shares were purchased in multiple transactions at prices ranging from $2.6800 to $2.8400, inclusive. The Reporting Persons undertake to provide, upon request by the Staff of the Securities and Exchange Commission, full information regarding the number of Common Shares purchased at each separate price within the ranges set forth in this footnote.

(6) The price reported for the Common Shares purchased by TRT Holdings on February 12, 2016 is the weighted average price. The Common Shares were purchased in multiple transactions at prices ranging from $2.8200 to $3.100, inclusive. The Reporting Persons undertake to provide, upon request by the Staff of the Securities and Exchange Commission, full information regarding the number of Common Shares purchased at each separate price within the ranges set forth in this footnote.

(d)                                               No person other than the Reporting Persons is known to have the right to receive, or the power to direct the receipt of dividends from, or proceeds from the sale of, the Common Shares.

(e)                                                Not applicable.

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SIGNATURE

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

Dated as of: February 16, 2016

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