Exhibit 21
SIGNIFICANT SUBSIDIARIES
CLEVELAND-CLIFFS INC. AS OF DECEMBER 31, 2017
Name
Cliffs' Effective Ownership
Place of Incorporation
Cleveland-Cliffs International Holding Company
100%
Delaware, USA
Cleveland-Cliffs Ore Corporation
100%
Ohio, USA
Cliffs Finance US LLC
100%
Ohio, USA
Cliffs Finance Lux SCS
100%
Luxembourg
Cliffs (Gibraltar) Holdings Limited
100%
Gibraltar
Cliffs (Gibraltar) Holdings Limited Luxembourg S.C.S.
100%
Luxembourg
Cliffs (Gibraltar) Limited
100%
Gibraltar
Cliffs Mining Company
100%
Delaware, USA
Cliffs Minnesota Mining Company
100%
Delaware, USA
Cliffs Natural Resources Pty Ltd.
100%
WA Australia
Cliffs Natural Resources Holdings Pty Ltd.
100%
WA Australia
Cliffs Natural Resources Luxembourg S.a.r.l
100%
Luxembourg
Cliffs TIOP Holding, LLC
100%
Delaware, USA
Cliffs TIOP, Inc.
100%
Michigan, USA
Cliffs TIOP II, LLC
100%
Ohio, USA
Cliffs UTAC Holding LLC
100%
Delaware, USA
The Cleveland-Cliffs Iron Company
100%
Ohio, USA
Tilden Mining Company L.C.
100%
Michigan, USA
Lake Superior & Ishpeming Railroad Company
100%
Michigan, USA
Cliffs PinnOak LLC
100%
Ohio, USA
Cliffs Marquette, Inc.
100%
Michigan, USA
Marquette Iron Mining Partnership
100%
Michigan, USA
Northshore Mining Company
100%
Michigan, USA
Pickands Hibbing Corporation
100%
Minnesota, USA
Cliffs Pickands Holding, LLC
100%
Delaware, USA