Horizontal hydraulic fracturing, which makes oil and gas in deep, dense shale easier to reach, turned the U.S. into the world's top energy producer before the crash. But the oil bust "has erased tens of thousands of jobs in the drilling and service sectors, dried up local tax revenues and charitable largess that flowed along with crude oil to Texas, North Dakota and Oklahoma," Jennifer Hiller reports for Reuters. It has also meant less income for about 12 million rural Americans who receive royalty checks for allowing frackers to drill on their land.

For example, Paul Ruckman, a retiree in DeWitt County, Texas, used to receive enough royalty money to build a six-bedroom vacation home with plenty left over, but told Hiller his checks have dropped 70 percent since January and said he imagines it'll get worse.

"Royalties, which can range from 12.5% to 25% of the value of oil and gas pumped, helped revitalize DeWitt and other communities in oil patches across the United States," Hiller reports. "The average oil-land owner collects about $500 a month, according to the National Association of Royalty Owners, but that will not last."