During Operation Circle Pines from 29 March to 5 April 1966, the 1st Battalion, 5th Infantry Regiment attacked the woods and discovered that the VC had built extensive bunker and tunnels systems with some of the tunnels three or four levels deep.

[2] On 10 June 2013 the 1/27th Infantry was awarded a Presidential Unit Citation for its actions on 19 July 1966.

[3][4] In 1973 the Ho Bo area was flat, almost featureless terrain, laced with trenches and tunnels, deeply pocked with ragged lines of bomb craters left by numberless waves of B-52s, its shattered plantations overgrown with head-high weeds and dense brush.

Nearly 10 years of battle littered defaced the countryside, and a tangle of tank-tread marks gave it the appearance of an abandoned armored training ground.

Hidden beneath were the bunkers and fighting positions of several People's Army of Vietnam main force units, the principal occupant being the 101st Infantry Regiment which had first entered the southern battlefield in 1966 from North Vietnam and had been a more or less constant resident of the Tây Ninh-Hậu Nghĩa -Bình Dương region since then.