Imagine a gold rush in which nobody actually has to bother panning for gold, an oil boom without any unsightly oil wells and a lottery that pays out proceeds for a lifetime. Picture entire neighborhoods suddenly making out like Jed Clampett.

Think of all that, and you can come close to understanding the wild good fortune that has recently bubbled up under the feet of hundreds of thousands of residents in and around this North Texas city, which just happens to be located atop what experts predict could be the largest onshore natural gas field in the United States.

They call it the Barnett Shale, a vast underground gas reservoir trapped inside the bedrock stretching beneath 5,000 square miles in and around metropolitan Fort Worth. For decades, geologists have known the gas was there, but it had always lain just beyond the reach of the drilling technologies needed to break it free.

Not anymore. A recent convergence of high natural gas prices, new drilling techniques and a growing national demand for the clean-burning properties of the fuel has set off a mad dash by competing gas companies to lock up drilling rights in virtually every Fort Worth area neighborhood -- with long lines of property owners eager to sign up.

The toughest decision for many homeowners seems to be what to do with the unexpected gas royalties they are suddenly reaping, which can average $250 per acre, per month. So far, swimming pools and summer homes seem to be popular choices.

"This is free money," said Francis Leong, former mayor of the Fort Worth suburb of Haslet, who organized neighbors to pool their land parcels, making them more attractive to a drilling company. "The only complaints I get are from people wanting to know why they aren't drilling more wells."

This land rush is proving to be particularly democratic, benefiting rich and poor and everyone in between. Nolan Catholic High School in Fort Worth will be getting royalties, as will the Shiloh International Church of God, a storefront church nearby. The Woodhaven Country Club has signed a lease for its 150 acres, as did the Circle T Girl Scout Council, which has a 112-acre summer camp north of Fort Worth that could, with a little luck, soon be generating tens of thousands of dollars each month.

"We're trying not to bank on anything yet, because they just started surveying and you can't build a budget on money you don't have," said Patricia Thomson, chief executive officer of the scout group. "But considering we have a $3.5 million budget we have to raise every year, [gas royalties] would help a lot."

Best of all, from the perspective of many property owners, the natural gas wells are nearly invisible. More than 4,000 wells have been drilled across the metropolitan area, but most residents would be hard-pressed to find them. Using a new technology known as "horizontal drilling," gas companies can tap 40 acres underground with a single well drilled straight down for a mile and a half, then angled 90 degrees to run parallel to the surface.

That means that a gas company can extract the gas from beneath an entire golf course by drilling a handful of wells far from any fairways.

The drilling process involves a noisy portable rig churning and squealing 24 hours a day. But once the drilling is completed after about three weeks, the only traces of the gas well are some small pipes and valves protruding above ground and a couple of metal tanks about the size of a shipping container. That is nothing like the huge, bobbing, steel horse-head of a typical oil well pump.

The only other temporary neighborhood disruption involves the digging of trenches to lay new feeder pipelines to carry the gas from the wells to larger collection points. But those cuts are quickly filled in, replanted or paved over.

There are some environmental risks. A poorly drilled gas shaft could perforate groundwater reservoirs, contaminating a resource that in arid Texas is often more precious than oil or gas. Millions of gallons of water and sand, injected under high pressures to fracture the bedrock and release the gas, can pollute a drill site if not disposed of properly.

And there is always the danger of a blowout, releasing deadly, invisible gas that can poison nearby residents and cause a devastating explosion.

A blowout happened early on during the drilling in Leong's neighborhood about two years ago. A well burst and released enough odorless gas to cause authorities to order a local evacuation for several hours.

"Nobody was too alarmed," Leong said. "The company came right out and fixed it, and we haven't had any problems since. It certainly wasn't enough to cause anyone to want the drilling to stop."

Nor do the potential dangers seem to be much of a deterrent to many other property owners in the region, who have been courted by competing gas drilling companies racing door to door to sign as many leases as they can to rope off neighborhoods from rivals.

Larry Brogdon, a partner and lead geologist of the Four Sevens Oil Co. in Fort Worth, keeps track of his firm's progress with a series of huge maps lining his office walls. Vast swaths marked in red represent 16,000 acres under lease so far and testify to the success of the company's sales pitch, delivered at community meetings, block parties and barbecues.

"We tell them this is like getting an annuity -- they'll be getting royalties for a long time," Brogdon said, adding that some of the wells might produce gas for a century.

Although the Barnett Shale gas deposits vary and not all of them can be profitably extracted using current technologies, energy experts predict that nearly every property owner in metropolitan Fort Worth who also owns the mineral rights beneath the land could eventually benefit from the boom.

Until three or four years ago -- before the potential of the Barnett Shale grew apparent -- those mineral rights were regarded as virtually worthless and were routinely conveyed along with the deed to a property.

The only real losers in the gas scramble appear to be renters, landowners in downtown Fort Worth (where urban density and underground utilities make drilling impractical) and anyone who bought property recently.

"There's a new subdivision not far from here, but the developers nowadays won't sell the mineral rights," Leong said. "So those folks are kind of out of luck."