USA Today: Ten states accounted for roughly 94% of all onshore U.S. reserves as of the end of 2011, with roughly a third of this in Texas alone just over 7 billion barrels. In many of these states, the oil industry is a major part of their economies. Based on the U.S. Energy Information Administration's data on proved oil reserves by states, these are the most oil-rich states in the country. These states process the vast majority of the oil refined in the U.S. each year. Of the nation's 139 operating refineries,...