In this Wednesday, April 15, 2009 photo, an unidentified worker passes a truck owned by Halliburton while being used at a remote site for natural-gas producer Williams in Rulison, Colo. Halliburton Co. said Monday, April 20, its first-quarter earnings tumbled 35 percent as oil and natural gas producers, stung by low prices, cut back on exploration and drilling. (AP Photo/David Zalubowski)