During the Vietnam War not all transport between different bases was provided by helicopters, it was essential to use roads and tracks between locations and keep them securely open for all kinds of vehicles (military and civilian) and people. That meant keeping hundreds of teams of soldiers out on the roads checking them regularly for mines and booby-traps set by both the local Viet Cong and their North Vietnamese comrades. Here two U.S. Marines are carefully checking a suspicious patch of ground which the U.S. Army P-158 Mine Detector has alerted them to. As the kneeling ‘Grunt’ gently prods the ground with his M16 bayonet his buddy carrying both of their M16’s looks on.