About 1.7 Billin tons of mineral wastes are discarded annually in the United States. The total accumulated mineral solid wastes amounted to about 25 billion tons. These mineral waste piles currently cover more than 2 million acres. They are second only to agricultural wastes in quantity and represent nearly 40 percent of the total solid wastes produced in the United States. A part of the mineral discard is fine-size material requiring some sort of stabilization if air and water pollution are to be minimized. On active mill tailing ponds, air pollution is controlled by keeping the surfaces of the ponds wet either by tailings discharge or by sprinkling. On inactive ponds, a more permanent solution is required, usually that of physical, chemical, or vegetative stabilization. Other physical methods of stabilization evaluated include (1) the use of bark covering and (2) the harrowing of straw into the top few inches of tailings.