The Eagleville oil field in South Texas, discovered only in 2009, is the largest in the US, according to a supplement to a report from the US Energy Information Administration called “US Crude Oil and Natural Gas Proved Reserves, 2013.” EIA respectively ranked the top 100 oil and gas fields in the US based on estimated 2013 proved reserves. Actual proved reserves numbers by field, however, were not disclosed. The agency’s last top 100 rankings covered 2009 estimated proved reserves. Eagleville spans 14 counties and boasted 238 million bbl in production during 2013. It and Briscoe Ranch represent two new additions from the Eagle Ford to both the top 10 and top 100 US oil fields.