ST. LOUIS -- Blessed with natural resources but never enough jobs, southern Illinois counties have begun sampling the fruits of a land rush driven by hydraulic fracturing, or "fracking."Hundreds of thousands of dollars in fees have flowed into county coffers from a stream of landmen, who converged in recent years to scour title records for prime parcels for exploration. County clerks funneled much of that windfall into digitizing bulky, age-yellowed record books that took a toll from all the frenzied searches.A coffee shop owner credits the visitors with saving her business in Wayne County's tiny Fairfield, east of St. Louis. The county's finance board leader says he has seen more locals sporting new vehicles and spending more on items at auctions, thanks to land deals tied to the drilling push.Locals believe the best is yet to come. But, as lawmakers in Springfield argue about potentially groundbreaking regulations that would facilitate the use of hydraulic fracturing, the oil and gas production technique that has helped spawn booms around the country, it's difficult to determine how much of the region stands to benefit. Industry officials say at least 17 counties -- perhaps a sixth of the state -- could see some activity, and that landowners already have leased perhaps half a million acres."Once they hit a well, everybody and their dog will be in here drilling," said Steve Ehrhart, head of the finance committee in Wayne County, which has been one of the epicenters of the land speculation.For many in the region, where oil rigs dot the landscape and coal mines long have been king, there's broad hope of bigger financial gains.Of special intrigue is the region's New Albany Shale, a formation roughly 5,000 feet below the surface. While the industry says the formation underlies some two-thirds of the state, land is being leased in about 17 southern counties where the shale is deepest and believed to be most likely to yield significant production.Gov. Pat Quinn and industry groups say new drilling could create as many as 40,000 jobs, by some estimates. Many counties in this often-struggling, largely rural region say could use the jobs they're convinced would come from drilling and related services.For now, fracking is waiting on state lawmakers, who will resume weighing how to regulate it when they return to Springfield next week. Industry groups and some environmental groups have crafted a compromise that would implement some of the toughest regulations in the country, but other environmentalists are demanding a moratorium until the impact can be further studied.Brad Richards, the Illinois Oil and Gas Association's executive vice president, called the estimate of a half-million acres leased for future drilling conservative. Energy companies must file their leases with the counties, but many may be waiting for competitive reasons. Because they're not kept in one central location for the state -- along with the fact that leases are filed manually rather than electronically -- it's difficult to easily discern how much acreage is under lease.Hamilton, Wayne and White counties, where oil and gas drilling has taken place for decades, are among the hottest targets for prospectors, though leases also are being acquired in two counties -- Johnson and Pope -- where there never has been drilling, Richards said.It's been good for the bottom line of Hamilton County, where clerk and recorder Mary Anne Hopfinger says her office has reaped some $450,000 just in the past two years.