Maybe it’s Manifest Destiny — or maybe it’s just the instinct of all creatures to return to their home. Whatever the reason, the gray wolf, once exterminated from Northern California and southern Oregon, is slowly making its way westward from the Rockies. As its arrival becomes ever more imminent, battle lines are being drawn. Defenders of Wildlife has petitioned the federal government to set aside 16 millions acres of national forests and parks in the region as wolf habitat. But sheep and cattle ranchers, who already claim to be burdened by federal efforts to protect species, are worried about their livestock. Defenders estimates that about 500 gray wolves could make their home in the 16 million acres within a couple of years.