The United States, according to the U.S. Energy Information Administration, is the top natural gas producer and consumer in the world, and with its 273 trillion cubic feet of proven reserves, the United States holds the fourth largest source of natural gas deposits globally.
Thanks to improvements in extraction and mining, much more of the country's energy deposits are within reach than ever before.
Not surprisingly, companies are trying to get their hands on as much as they can. But according to the U.S. Geological Survey, there is the potential for even more. So, where are the country's five largest potentially undiscovered shale gas reserves?
88,145.68 Billion Cubic Feet
3,463.13 Million Barrels of Liquid Natural Gas
Stretching from Alabama all the way to upstate New York by way of the Appalachian Mountains, the Appalachian Shale Basin is at the top of this list with more than an estimated 88,000 billion cubic feet of shale natural gas yet to be found.
The region is in the midst of explosive natural gas development since 2005, especially in Pennsylvania and Ohio, where estimates anticipate the Marcellus Shale Formation in Pennsylvania could lead the country's production of natural gas in the next few decades. However, the region is hampered by geography as a vast majority of its shale is located in mountainous regions.
The basin also encompasses the Utica Shale deposit that lies underneath Ohio.
Already known as the country's leader in oil, Texas could be a natural gas powerhouse in the future with two of the top as-of-yet undiscovered shale gas deposits.
Stretching from El Paso to Lubbock, Texas, and from Clovis, New Mexico, to Del Rio, Texas, the Permian Basin is next on our list, with an estimated 35,130 billion cubic feet (bcf) of undiscovered shale gas.
By contrast, the average consumer in Texas uses 607,000 cubic feet of natural gas a year.
The state is already in the midst of a natural gas boom in the southern portion of the state.
Overlapping Arkansas and Oklahoma, the Arkoma Basin is said to potentially hold 26,670 bcf of natural gas.
Bend Arch-Fort Worth Basin
Back in Texas, the Bend Arch-Fort Worth Basin is next on our list with 26,228 bcf of natural gas yet to be found. Stretching from Wichita Falls to San Antonio, the USGS' assessment predicts that most of the state has some level of recoverable shale-locked natural gas.
The basin holds the Barnett Shale formation which has prompted large-scale hydraulic fracturing near the high-density areas of Fort Worth and its suburbs.
Straddling the Kansas, Texas and Oklahoma state lines lies the Anadarko Basin, said to hold 22,823 bcf of shale gas.