<SEC-DOCUMENT>0000764065-17-000047.txt : 20170222
<SEC-HEADER>0000764065-17-000047.hdr.sgml : 20170222
<ACCEPTANCE-DATETIME>20170222173535
ACCESSION NUMBER:		0000764065-17-000047
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20170217
FILED AS OF DATE:		20170222
DATE AS OF CHANGE:		20170222

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			CLIFFS NATURAL RESOURCES INC.
		CENTRAL INDEX KEY:			0000764065
		STANDARD INDUSTRIAL CLASSIFICATION:	METAL MINING [1000]
		IRS NUMBER:				341464672
		STATE OF INCORPORATION:			OH
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		200 PUBLIC SQUARE
		STREET 2:		STE. 3300
		CITY:			CLEVELAND
		STATE:			OH
		ZIP:			44114-2315
		BUSINESS PHONE:		216-694-5700

	MAIL ADDRESS:	
		STREET 1:		200 PUBLIC SQUARE
		STREET 2:		STE. 3300
		CITY:			CLEVELAND
		STATE:			OH
		ZIP:			44114-2315

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	CLEVELAND CLIFFS INC
		DATE OF NAME CHANGE:	19920703

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Mee Terrence R
		CENTRAL INDEX KEY:			0001511746

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-08944
		FILM NUMBER:		17629754

	MAIL ADDRESS:	
		STREET 1:		1100 SUPERIOR AVENUE
		STREET 2:		15TH FLOOR
		CITY:			CLEVELAND
		STATE:			OH
		ZIP:			44114
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_148780291969699.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2017-02-17</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000764065</issuerCik>
        <issuerName>CLIFFS NATURAL RESOURCES INC.</issuerName>
        <issuerTradingSymbol>CLF</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001511746</rptOwnerCik>
            <rptOwnerName>Mee Terrence R</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>200 PUBLIC SQUARE, SUITE 3300</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>CLEVELAND</rptOwnerCity>
            <rptOwnerState>OH</rptOwnerState>
            <rptOwnerZipCode>44114</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>EVP, Global Commercial</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Shares</value>
            </securityTitle>
            <transactionDate>
                <value>2017-02-17</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1365</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>11.49</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>259297.543</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Shares</value>
            </securityTitle>
            <transactionDate>
                <value>2017-02-21</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>22142</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>281439.543</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Surrender of shares in payment of tax liability incurred on February 17, 2017, the date distribution of vested restricted stock units to the Reporting Person granted in 2014.</footnote>
        <footnote id="F2">Reflects the number of restricted share units granted to the Reporting Person on February 21, 2017 from the Cliffs Natural Resources Inc. 2015 Equity and Incentive Compensation Plan. This grant vests on December 31, 2019.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ James D. Graham by Power of Attorney</signatureName>
        <signatureDate>2017-02-22</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
