Cattle graze in a field as gas flares from a pumping installation on the Eagle Ford Shale in Karnes County. The shale oil boom is going strong here south of San Antonio on a formation that stretches for about 300 miles across south Texas, one of the most prolific oil patches in the United States, In some areas the oil companies have discovered "sweet" spots and they are still drilling, while other areas have been cut back. Excess gas is burned off at oil pumping stations which dot the countryside.