In addition to the Military Region IV headquarters, the other Viet Cong units in the area were suspected to be the 272d Regiment, the 1st and 7th Battalions of Military Region IV under the 165th Viet Cong Regiment, the Phu Loi Local Force Battalion, plus three local force companies. Other intelligence sources indicated the 2d, 3d, and 8th Battalions of the 165th Viet Cong Regiment might also be encountered. The Thanh Dien forest and the Iron Triangle were known to Page 22 contain strongly fortified positions with the routes of approach mined and booby trapped. The terrain in the area consists of dense forests and wet, open rice lands. Cover in the rice paddies, marshes, and swamps is generally limited to road embankments and dikes.
Fields of fire are poor in the forests.
Vehicle movement is restricted to existing roads and some trails. The weather for Cedar Falls was most favorable during January when the northeast monsoon develops to its fullest, leaving the interior regions of the III Corps area with relatively clear skies and little precipitation. Except for periods of early morning fog and occasional morning and afternoon rain showers, cloud ceilings are unlimited and the visibility is excellent. The deception planned in positioning the various units was involved and critical. Page 23 borne Brigade was operating between Ben Cat and Phuoc Vinh.