The Caddo Lake National Wildlife Refuge in Karnack, Texas, is midway through a project of busting up 90,000 tons of concrete slab. Building foundations are some of the last remnants that remain of the former Longhorn Army Ammunition Plant. The land is being turned into old growth forest by the U.S. Fish and Wildlife Service. Refuge manager Mark Williams says the contractor's biggest customer is the State of Louisiana, which wants all of the fill for the construction of I-49.