Observation Post 1 (OP1) was located on a hill just north of FSB Hill 4-11 and the Song Tra Khuc River. It was home to a forward observing unit from the 251st Forward Artillery and to a company of Montagnards and their families. OP1 was in the area of operations for the 3rd Battalion, 1st Infantry. During 1969, 1970, and 1971, the line companies from this battalion constantly patrolled the area around OP1.
Your tour guide for OP1 is John Keen, who was a Forward Observer with the 251st Field Artillery Detachment. He took these pictures between April and December of 1969.