A biennial survey of U.S. gas reserves has just printed its highest-ever estimate, reports the Financial Times.

The Potential Gas Committee says there is now 2,384 trillion cubic feet of recoverable natural gas in America, up 486 tcf from the previous all-time high in 2010.

Most of the new reserves came from recalculations in the Atlantic, Rocky Mountain and Gulf Coast areas.

Here’s why it went up, according to PGC Director John Curtis, via PGC’s release: