The President of the United States of America takes pride in presenting the Silver Star (Posthumously) to Lance Corporal Dennis H. Riley (MCSN: 2553936), United States Marine Corps, for conspicuous gallantry and intrepidity in action while serving as a Patrol Leader with Combined Action Platoon 1-4-4, III Marine Amphibious Force, in connection with combat operations against the enemy in the Republic of Vietnam. On 31 December 1969, while participating in a joint operation, Lance Corporal Riley’s patrol, a Regional Forces unit, and a Popular Forces unit came under a heavy volume of small arms and was fire from North Vietnamese Army soldiers occupying well-concealed emplacements. During the initial moments of the attack, the commander of the Regional Forces unit was seriously wounded. Unhesitatingly assuming command of the unit, Lance Corporal Riley fearlessly moved across the fire-swept terrain to shout encouragement and directions to the men and frequently maneuvered to dangerously exposed positions to observe enemy activities and deploy his units into more effective locations. During the course of the ensuing fierce fire fight one of the Regional Forces soldiers entered a mined area and detonated an enemy anti-personnel mine which killed him and a companion and seriously wounded a Marine. Lance Corporal Riley boldly entered the mine field, picked up his comrade, carried him to a covered location, and requested a medical evacuation helicopter. He then re-crossed the mined area and carried the wounded Regional Forces commander back to a place of relative security. With the arrival of the evacuation aircraft and an accompanying gunship, he skillfully directed fire at hostile positions, forcing the enemy to withdraw and enabling the casualties to be evacuated safely. In a final act, Lance Corporal Riley again entered the uncharted mine field and assisted in recovering the two mortally wounded Regional Forces soldiers. His heroic and determined actions inspired all who observed him and minimized friendly casualties. By his courage, dynamic leadership, and unwavering devotion to duty in the face of grave personal danger, Lance Corporal Riley upheld the highest traditions of the Marine Corps and of the United States Naval Service.