Exhibit 21

SIGNIFICANT SUBSIDIARIES
CLIFFS NATURAL RESOURCES INC. AS OF DECEMBER 31, 2014
Name
Cliffs' Effective Ownership
Place of Incorporation
Cleveland-Cliffs International Holding Company
100%
Delaware, USA
Cliffs (Gibraltar) Holdings Limited
100%
Gibraltar
Cliffs (Gibraltar) Holdings Limited Luxembourg S.C.S.
100%
Luxembourg
Cliffs (Gibraltar) Limited
100%
Gibraltar
Cliffs Finance US LLC
100%
Ohio, USA
Cliffs Finance Lux SCS
100%
Luxembourg
Cliffs Minnesota Mining Company
100%
Delaware, USA
Cliffs Natural Resources Luxembourg S.à r.l.
100%
Luxembourg
Cliffs TIOP Holding, LLC
100%
Delaware, USA
Cliffs TIOP, Inc.
100%
Michigan, USA
Cliffs UTAC Holding LLC
100%
Delaware, USA
Northshore Mining Company
100%
Delaware, USA
The Cleveland-Cliffs Iron Company
100%
Ohio, USA
United Taconite LLC
100%
Delaware, USA