That is only part of the federal EPA requirement. Some states also require Oxygenated fuel.
In addition, the Renewable Fuel Standard requires a level of total percentage of the total gasoline used in the US. Although the metro area and state requirement contribute towards meeting this goal, it does not fulfill it. That forces companies to also add ethanol to their gasoline outside the metro areas or be fined.
http://www.gpo.gov/fdsys/pkg/FR-2012-01-09/pdf/2011-33451.pdf
There still are locations without ethanol, but it is not all areas outside large metros.
I wonder what the total cost of the ethanol boondoggle has been --
a. Additional costs to the economy attributable to using ethanol as a fuel...
b. And additional costs to the economy attributable to rising food prices...
Could ethanol be the most expensive boondoggle in world history? I wouldn't be surprised...