Oil Sands Mining

Marathon owns a 20 percent outside-operated interest in the Athabasca Oil Sands Project (AOSP), which includes the Muskeg River Mine, the Scotford Upgrader, and over 300,000 acres of potentially mineable land in Alberta, Canada. This asset gives Marathon access to stable, long-lived Organization for Economic Co-operation and Development (OECD) production that will be increased through several phased expansions over the next decade.

Marathon's AOSP interests were acquired when the Company purchased Western Oil Sands Inc. in October 2007 in a transaction valued at approximately U.S. $6.9 billion, including debt assumptions.