The Sixth Marine Division

by James R. Stockman

Map 5. Final Drive. Motobu Peninsula.

All during the fighting on Motobu, the men of the Sixth Marine Division had heard stories of the fighting down south. They knew that the Tenth Army had uncovered the main Japanese defensive positions; that the enemy had chosen rough hilly ground across a narrow part of the island. The enemy was well dug in on a high and broken hill mass which took its name from its geographical center—Shuri. The line, or series of lines really, ran from north of Naha through Shuri to Yonabaru on the east coast. They had heard that the XXIV Corps had run into a virtual stalemate; that some sixty thousand of the enemy were offering fierce resistance from concealed positions; that the enemy was using mortars and artillery on an unprecedented scale; and that the enemy troops in southern Okinawa were excellent soldiers, well disciplined, and well prepared to fight a long and costly campaign. Before the second week in May had passed the men were certain that none of the stories were exaggerated.

In the new zone of action, the Sixth Marine Division launched its first attack when it sent the Twenty Second Marines across the Asa River in the early morning hours of 10 May. Patrols had crossed the river on the previous day and reconnoitered the ground to its immediate south. The only bridge across the river in this sector had been totally destroyed. Through the night of 9-10 May, the Sixth Engineer Battalion worked to construct a footbridge. Although the little bridge was finally completed in time for the pre-dawn attack, a group of the enemy carrying demolitions packs succeeded in destroying themselves and a section of the bridge before many of the Marines got across.

At 0330, 10 May, the First and Third Battalions of the Twenty Second Marines crossed the Asa; the First waded across upstream on the regiment’s left, while the Third started to use the footbridge. When it was destroyed, the battalion was forced to go upstream and wade across. At first enemy resistance was light, but as the Japanese became aware of this threat to their left flank, opposition became fierce. Despite heavy artillery, mortar, and small arms fire, the troops moved on up the first ridges. By nightfall, and after a day of heavy casualties, a bridgehead 1400 yards wide and about 400 yards deep had been established.

Next morning the reserve battalion of the Twenty Second Marines, the Second, was committed to cover the left flank of the First which was fighting to reduce an enemy stronghold on a formidable coral hill southeast of Asa village. When flanking action failed to secure the hill, the troops withdrew so that naval gunfire from the USS Indianapolis could be utilized. In the meantime the engineers labored under sporadic enemy fire to construct a Bailey Bridge across the Asa, where the footbridge had been. About noon the structure was completed and tanks roared across to support the troops. With the added fire power of the tanks, the First Battalion attacked the hill again, this time successfully. Over on the right, the Third Battalion fought for three hours before capturing the precipitous cliff area in its zone of action.

On 12 May the Twenty Second Marines, with all three battalions in the line, continued to advance despite increasing enemy resistance. Not only was the regiment receiving fire from its front, but also from the left flank, where the enemy in his positions on Wana Ridge and the Shuri heights could observe troop movements and bring fire to bear at an instant’s notice. As it became apparent that the division’s left was becoming open, General Shepherd ordered the Third Battalion, Twenty Ninth Marines into the line to protect the east flank. It was quite plain that another regiment would have to be committed if the momentum of advance were to be maintained.

Next day, the Sixth Marine Division continued the attack with the Second Battalion, Twenty Second Marines and the Third Battalion, Twenty Ninth, in assault. About three hundred yards was all that could be gained due to heavy enemy resistance. In the late afternoon the other two battalions of the Twenty Ninth Marines moved up behind the Third, and prepared to go into the assault on 14 May.

By this time General Shepherd had discovered the following: (1) In attempting to outflank the Shuri line, the Sixth Marine Division had uncovered the western anchor of the enemy’s main defensive position; (2) Three terrain features, heavily fortified and manned, and mutually supporting formed this anchor; (3) Unprotected but heavily guarded corridors led into each of these terrain features. (4) There was no ground offering covered routes of approach, from which these terrain features could be assaulted; (5) the three terrain features (later called Horseshoe Ridge, Sugar Loaf Hill, and Half Moon Hill) would be held by the enemy at all costs; if they were lost, the enemy’s main position at Shuri would be outflanked; (6) The battle efficiency of the Twenty Second Marines was seriously impaired; It had lost over 800 men killed or wounded since crossing the Asa; (7) Naha, the capital city of Okinawa, lay open in front of the Twenty Second Marines, but it could not be seized until the Sugar Loaf defensive position, Horseshoe Ridge, and the Half Moon were reduced and cleared of enemy.

Map 6. Attack of 2nd Bn., 22nd Marines.