The Marcellus shale formation is estimated to hold roughly 500 trillion recoverable cubic feet of natural gas. And industry leaders expect you might be surprised at just how far that amount of natural gas can go.

For some perspective, consider that the United States now consumes about 63 billion cubic feet of natural gas each day, according to the U.S. Energy Information Administration. That means the Marcellus find alone could equate to a 20-plus year supply of U.S. natural gas consumption.

The vast Marcellus shale field - underlying West Virginia, Pennsylvania, Eastern Ohio and other states from New York to Tennessee - could also hold the key to helping the U.S. free itself from dependence on foreign sources of energy.

"Americans have an insatiable appetite for energy, and natural gas is a great solution," said Chesapeake Energy Director of Corporate Development Stacey Brodak.

Based upon the U.S. energy information, Consol Energy and CNX Gas Corp. spokeswoman Laural Ziemba said 500 trillion cubic feet of natural gas would be enough to do the following, based on current U.S. consumption rates:

Satisfy total U.S. natural gas demand for 22 years.

Satisfy total U.S. residential natural gas demand for 101 years.

Heat 43.1 million U.S. homes for 153 years.

Satisfy West Virginia and Pennsylvania natural gas demand for 1,908 years.

Chesapeake Energy spokeswoman Jacque Bland said 500 trillion cubic feet of gas could heat all U.S. homes, roughly 130 million of them, for more than 46 years.

Natural gas now powers nearly 120,000 vehicles operating on American roads, and many of those vehicles are in California. Some Los Angeles school buses are now running on natural gas, while public buses in Los Angeles and Atlanta also use the fuel.

With the price of gasoline fluctuating between $3 and $4 per gallon, the search for alternative fuels to power motor vehicles may lead to natural gas produced from the vast Marcellus shale field.

"With recent discoveries of recoverable gas, we can and should convert our infrastructure to use natural gas which will be abundant and dependable for years to come. It also burns cleaner than other fossil fuels, which can improve our environment," said Brodak.

Ziemba added, "Five hundred trillion cubic feet has the energy equivalent of 86.2 billion barrels of imported oil, which is enough energy to supply the U.S. Energy Information Administration's projected energy consumption from all of the light duty vehicles, commercial light trucks, buses and freight trucks on America's roads for the next 20 years."

During its recent session, the West Virginia Legislature adopted new tax credits to encourage the purchase of natural gas vehicles and provide credits for those looking to build alternative fuel filling facilities.

In terms of available passenger natural gas vehicles, one of the most popular is the Honda Civic GX, which will be renamed, simply, the Honda Civic Natural Gas for the 2012 model year. It now carries a fuel economy rating of 28 miles per gallon equivalent.