Exhibit 5.1

JONES DAY

NORTH POINT • 901 LAKESIDE AVENUE • CLEVELAND, OHIO 44114-1190
TELEPHONE: (216) 586-3939 • FACSIMILE: (216) 579-0212

March 7, 2011

Cliffs Natural Resources Inc.
200 Public Square, Suite 3300
Cleveland, OH 44114-2315

          Re:      Registration Statement on Form S-8 Filed by Cliffs Natural Resources Inc.

Ladies and Gentlemen:

     We have acted as counsel for Cliffs Natural Resources Inc., an Ohio corporation (the “Company”), in connection with the Company’s Amended and Restated Cliffs 2007 Incentive Equity Plan, as amended (the “Plan”). In connection with the opinion expressed herein, we have examined such documents, records and matters of law as we have deemed relevant or necessary for purposes of this opinion. Based on the foregoing, and subject to the further limitations, qualifications and assumptions set forth herein, we are of the opinion that the 9,000,000 common shares, par value $0.125 per share, of the Company (the “Shares”) that may be issued or delivered and sold pursuant to the Plan and the authorized forms of stock option, restricted share or other applicable award agreements thereunder will be, when issued or delivered and sold in accordance with such Plan and agreements, validly issued, fully paid and nonassessable, provided that the consideration for the Shares is at least equal to the stated par value thereof.

     The opinion expressed herein is limited to the laws of the State of Ohio, as currently in effect, and we express no opinion as to the effect of the laws of any other jurisdiction. In addition, we have assumed that the resolutions authorizing the Company to issue or deliver and sell the Shares pursuant to the Plan and the applicable award agreements will be in full force and effect at all times at which the Shares are issued or delivered or sold by the Company, and the Company will take no action inconsistent with such resolutions.

     In rendering the opinion above, we have assumed that each award under the Plan will be approved by the Board of Directors of the Company or an authorized committee of the Board of Directors.

     We hereby consent to the filing of this opinion as Exhibit 5.1 to the Registration Statement on Form S-8 filed by the Company to effect registration of the Shares to be issued and sold pursuant to the Plan under the Securities Act of 1933 (the “Act”). In giving such consent, we do not thereby admit that we are included in the category of persons whose consent is required under Section 7 of the Act or the rules and regulations of the Securities and Exchange Commission promulgated thereunder.

Very truly yours,

/s/ Jones Day

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