The Associated Press analysed data from the US Department of Energy, which painted a staggering picture.
The news service said the data concluded that coal exports reached 107 million tons of fuel worth almost $16 billion in 2011.
It was the most since 1991 and more than double the 2006 volume.
The increase in coal exports was mainly powered by fuel-hungry Asia.
Coal exports to South Korea leapt 81% last year to more than 10Mt.
Meanwhile, the AP said Japan purchased almost 7Mt of US coal in 2011, up 119%.
India secured 4.5Mt of coal from the superpower, marking an increase of 65%.