Doug Buchanan grins with relief when he sees the carcasses. He has just driven up a steep dirt road onto a vast, sunbaked mesa overlooking the Mojave Desert in western Nevada. There, a few feet from the trail, lie the corpses of two steers. A raven perches on one, the only object more than three feet above the ground on this pancake-flat plateau. Cattle, dead or alive, qualify as good news in Buchanan's line of work. If cattle are present, that means grazing is permitted, and that in turn means that this land is most likely not protected habitat for the desert tortoise.
