Two miles beneath northwest Louisiana's patchwork quilt of forests, cotton fields and pastures, dozens of drill bits are grinding their way toward what may be the nation's energy future.

The region around Shreveport has known oil and gas exploration for decades, but it's now buzzing anew as companies try to capitalize on one simple fact: Locked into cementlike shale formations thousands of feet underground are potentially huge quantities of natural gas.

The gas found in the area's Haynesville shale and in other shale formations throughout the country has changed the nation's energy outlook in just a few short years.

Some see abundant North American natural gas as the gateway to reduced dependence on foreign oil and a bridge toward carbon-free energy sources since gas is the lowest-emission fossil fuel.

Others say the surge in next-generation gas production isn't paying off as promised and threatens local water supplies.

Some even see it as another speculative bubble, driven by hype that will never deliver the fuel it promises.

What is happening in Haynesville is typical of what has happened or is likely to occur in the other shale regions — millions of dollars in investment, plenty of lawsuits against the drilling companies and concerns about the safety of the drilling techniques being used.

Until just a few years ago, the story of natural gas supply in the U.S. had been one of decline. Dozens of liquefied natural gas terminals were on the drawing board in the earlier part of the decade to help import the fuel from overseas.

But the marriage of two long-used drilling techniques — hydraulic fracturing and horizontal drilling — is showing potential.

For years, companies have used hydraulic fracturing — injecting water into underground formations to break apart rocks and release more oil and gas.

The Woodlands-based Mitchell Energy perfected the techniques in the Barnett shale formations in North Texas.

But it wasn't until Devon Energy acquired Mitchell in 2002 that engineers added horizontal drilling — turning the drill bit at a 90-degree angle to tap into a larger section of the strata.

Suddenly these dense formations that companies thought too expensive to drill are economically feasible.