Exhibit 3.25 State of Delaware Secretary of State Division of Corporations FILED 01:30 PM 12/09/2002 020752816-3599464 STATE OF DELAWARE LIMITED LIABILITY COMPANY CERTIFICATE OF FORMATION OF ANR HOLDINGS, LLC FIRST: The name of the limited liability company is: ANR HOLDINGS, LLC SECOND: The address of its registered office in the State of Delaware is: 2711 Centerville Road, Suite 400 Wilmington, Delaware 19808 The name of its Registered Agent at such address is: Corporation Service Company THIRD: The name and address of the authorized person is: Karin M. Writer Bartlit Beck Herman Palenchar & Scott 1899 Wynkoop Street, Suite 800 Denver, Colorado 80202 The undersigned has executed this Certificate of Formation of ANR Holdings, LLC on this 9th day of December 2002. /s/ Karin M. Writer Karin M. Writer Authorized Person