At division level, the reserve mission was filled by Colonel Russell E. Honsowetz’, 7th Marines, minus 2/7 (Lieutenant Colonel Noel C. Gregory), which on 30 March became the maneuver force for the Kimpo Regiment. As the division reserve, the regiment was to be prepared to assume at any time either a defensive or offensive mission of any of the frontline regiments. In addition, the reserve regiment was to draw up counterattack plans, protect the division rear, improve secondary line defenses, and conduct training, including tank-infantry coordination, for units in reserve. The 7th Marines, with 3/7 (Lieutenant Colonel Houston Stiff) on the left and 1/7 (Lieutenant Colonel George W. E. Daughtry) on the right, was emplaced in the vicinity of the secondary defense lines, WYOMING and KANSAS, to the rear of the 5th and 1st Marines. Another regiment located in the rear area was the 11th Marines. Its artillery battalions had begun displacement on 17 March and completed their move by 25 March. Early on the 26th, the 11th Marines resumed support of the 1st Marine Division. While the Marine artillery had been en route, U.S. Army artillery from I Corps supported the division. With the arrival on the 29th of the administrative rear echelon, the Marine artillery regiment was fully positioned in the west. For Colonel Frederick P. Henderson, who became the division artillery commander on 27 March, operational problems in western Korea differed somewhat from those experienced in the east by his predecessor, Colonel Bruce T. Hemphill. The most critical difficulty, however, was the same situation that confronted General Selden--the vast amount of ground to be covered and defended, and the insufficient number of units to accomplish this mission. To the artillery, the wide division front resulted in spreading the available fire support dangerously thin. Placement of 11th Marines units to best support the MLR regiments created wide gaps between each artillery battalion, caused communication and resupply difficulties, prevented a maximum massing of fires, and made redeployment difficult.[25] [25] Col Frederick P. Henderson ltr to Hd, HistBr, G-3 Div, HQMC, dtd 25 Aug 59, hereafter _Henderson ltr I_. In making use of all available fire support, the artillery regiment had to guard not only against the duplication of effort in planning or delivery of fires, but also against firing in the Panmunjom peace corridor restricted areas, located near the sector held by the Marine division’s center regiment. Moreover, the artillerymen had to maintain a flexibility sufficient to place the weight of available fire support on call into any zone of action.