Rex Tillerson

Andrew Harrer/Bloomberg

Rex Tillerson

Property Owner
What he does: CEO of ExxonMobil
In position since: 2006
Why he is powerful: ExxonMobil’s acreage holdings, which include owned and leased land for oil and gas exploration and production, totaled 10.2 million net acres in the U.S., including 2.3 million net acres offshore, according to its latest 10-K filing. The land may be simultaneously available to other lessees for unrelated uses, depending on how it is managed by the owner. The company, headquartered in Irving, Tex., reported revenue of $310.6 billion in 2009.