Strict environmental guidelines, including a billboard ban and a 1988 law requiring towns to join in regional planning and statewide forest and farmland conservation efforts, aim to protect the rustic beauty of this least populous state in the East. The forests of the Green Mountains, Vermont's backbone, turn crimson and gold in the autumn; sugar maples, whose syrup sweetens the economy, highlight the glorious display of color. In winter, when snow blankets hillsides, skiers descend on more than 50 resorts. Vermont is the leading producer of monument granite and marble.