On May 9th, Oregon became the first state in the country to restrict the use of Aminocyclopyrachlor (ACP), an herbicide marketed to kill weeds that ends up killing trees. In Oregon, ACP killed 2,000 majestic old-growth trees. This deadly chemical reportedly travels underground along tree root systems, passing the poison from tree to tree, and continuing to kill trees long after and far away from the original pesticide application.