A soldier assigned to the Headquarters and Headquarters Battery, 32nd Battalion, 31st Brigade, reaches for his gas mask after a simulated aerial chemical attack against their camp on McGregor Range, Fort Bliss, Texas. The chemical attacks are executed by Russian helicopters operated by members of Optec Threat Support Activity at Biggs Army Airfield in suport of ROVING SANDS 1997. ROVING SANDS is a multinational effort and is the largest military exercise on United States soil that allows training in a joint environment to hone command and control procedures and integrate new systems in Theater and Air Missile Defense