While earlier operations had pushed the 5th Division east into the Mây Tào Mountains, they were expected to return to the Hát Dịch during the rainy season.

In early June U.S. forces operating 15 km south of Blackhorse Base Camp observed PAVN moving towards the Hát Dịch.

While the 1st Brigade provided protection, the engineers would use Rome plows to enlarge two parallel trails that eventually met east of Highway 2 and a third that joined the two in Hát Dịch.

On 27 June the ARVN 18th Division commander General Đỗ Kế Giai sent a Ranger unit to probe the campsite which they found to be abandoned, but fell into a VC ambush.

A 1/11th ACR task force was dispatched to the scene that evening and the following morning arrived at the site of the battle finding ARVN and VC dead.