Oil and gas lawyers said a recent report by the U.S. Energy Information Administration showing the Marcellus Shale play to be the fastest-growing natural gas play in the United States serves as an affirmation for attorneys and law firms that have built their practices around the oil and gas industry in the Appalachian Basin.

According to the EIA report, which was released August 1 and is based on reports from oil and gas producers from around the country, the number of “proved” natural gas reserves — those that drillers are reasonably certain they can recover gas from — in the Marcellus Shale nearly tripled between 2009 and 2010.