It's a Stewart family tradition, passed down from generation to generation on their 880-acre ranch in southeast Idaho. A Stewart son escorts his unsuspecting girlfriend on horseback through a pine forest to a flat, treeless ridge the family calls the plateau. All the while, his family watches through binoculars from the living room, waiting for the young man to take the woman's hand and pop "the" question, exactly like his father, uncles, cousins and brothers did before him. Even from a half-mile or so away, the answer is evident. "You see her jumping up and down," says Brent Stewart, patriarch of a family that has run cattle in the Crow Creek Valley for 50 years. Stewart chuckles, but there's a tinge of sadness in his voice. Soon, if phosphate-mining companies have their way, that ridge overlooking the ranch and its 11 Stewart family homes will exist only in memory.