The oil and natural gas have always been there, locked in the rocks. But it wasn't until the U.S. developed a new technology (hydraulic fracturing, or fracking) that it became apparent that it could be liberated. That story has been written several times over. But an equally significant story has received less notice. In the last several years, a global glut of natural gas and oil production has developed, thanks to higher U.S. production and the desire of OPEC members to pump more oil in the face of lower prices. But rather than sit on their hands or shut wells, the U.S. fracking industry has evolved and innovated. Fracking has become a cheaper, more refined, and more effective means of getting at fossil fuels. So while the price of both natural gas and oil has fallen sharply in recent years, so too has the break-even point for profitable extraction.