Pete Dube, who is from Buffalo, Wyo., pulls up in a pickup hauling a trailer with six horses and looks out across his land. In 1995, when he bought the 5,000-acre ranch in the Middle Prong Valley of the Powder River basin, nothing much disturbed the landscape except the deer, the pronghorn and the few cows that grazed the rolling hills and valleys.
Today semis are thundering along new dirt roads, heavy bulldozers are digging trenches for pipelines, overhead power lines are crisscrossing the valley, and drilling rigs are going up like mushrooms after a spring rain. Dube's spread is...