 While the 1st and 3rd Brigades were patrolling the Kim Son Valley between 11 and 27 February, Colonel William R. Lynch's 2nd Brigade closed down operations north of the Lai Giang and transferred his command post to Landing Zone Pony just east of the valley.The move was triggered by Colonel Doan's revelation that the 2nd Regiment was operating in the mountains southeast of Pony, information that seemed to be confirmed when radio intercepts indicated the presence of a major PAVN/VC headquarters there.On 16 February Lynch began a block and sweep of the suspected terrain.