The Fight on the Tanapag Plain
27th Division
6 July 1944

Background: The Attack on 5 July

by US War Department

On 5 July the battle for Saipan was ending its third week. Since the initial landings on Saipan, 15 June, the three divisions of the V Amphibious Corps had been in almost continuous and very bloody action. Though their losses had been high and the troops were tired, the 2d and 4th Marine Divisions and the 27th Division had kept plugging; the close of their task was now in sight. The Japanese forces were penned in the northern end of the island, and out of 30,000 enemy troops, it was estimated that only 5,000 to 7,000 were left, supported by one battalion of 77 mm guns and perhaps 20 of an original 100 tanks.

Every indication, including the testimony of prisoners, pointed to a complete breakdown of enemy communications and to his serious difficulties with respect to food, water, and hospital facilities. The Japanese faced also a shortage of small-arms weapons. Many of their remaining units were disorganized by losses of officers, and the state of their morale was questionable. Information found in documents captured on 4 July confirmed other evidence that there were two principal centers of resistance in the area, five miles deep, still held by the enemy: near the Marpi airfield, zone of the 4th Marine Division, and at Paradise Valley, facing the 27th Division.

These two divisions held the US line 5 July, the 2d Marine Division having been pinched out the day before. Lt. Gen. Holland M. Smith, USMC, commanding V Amphibious Corps, was preparing for the assault on Tinian Island and wanted the 2d Marine Division to be rested for this action. The 27th Division, commanded by Maj. Gen. George W. Griner, held the western end of the front with two regiments on line in a zone one and a half miles wide. The 106th Infantry was in divisional reserve. On 5 July his two forward regiments were to attack abreast from a line of departure with objectives 4,000 yards to the northeast.

The terrain differed greatly in the two regimental zones. To the right, the 165th Infantry was advancing in the rugged hills that characterize the interior of Saipan Island. These hills terminate sharply in an escarpment marked by frequent stretches of cliff. Below the steep wall paralleling the shoreline an 800-yard strip of coastal plain, flat or slightly rolling, bordered the Saipan beach. This coastal plain, and the edge of the hills that dominate it, fell in the zone of the 105th Infantry.

Neither attacking regiment of the 27th Division made much headway on 5 July. At the day's end the 105th, with which this account is mainly concerned, was still short of the planned line of departure, although the left-wing units along the beach had advanced some 1,500 yards. This move had been made through terrain not previously reconnoitered, in which the Japanese had constructed extensive defenses to resist landings on the beach-. Almost no opposition was encountered in these emplacements, but each in turn had to be carefully worked through, and this took time. As the line of departure was neared, some fighting began to develop all along the line, particularly to the right on the hills that walled the coastal plain.

A main road ran northeast along the beach, leading from Tanapag to the north of Saipan. Almost paralleling it was a narrow-gauge railroad, single-tracked, for service of the sugar plantation industry. Close to the line of departure, at Road Junction 2, a main road branched off east, into the hills and across the island. Just south of this junction was the most prominent landmark on the almost bare coastal plain: a large coconut grove, with tall grass beneath the trees.

The 2d Battalion, 105th Infantry, moved up into this area on the afternoon of 5 July, working along the coastal plain with E and F Companies abreast (Map 1, below). Company E, mopping up enemy defensive positions in a series of platoon actions, had finally pushed almost to Road Junction 2 when the advance stalled under intense machine-gun fire. Patrols decided that the enemy had set up one or two guns in an old landing barge which was beached on the left flank. Two tanks were sent along the coastal highway beyond the road junction, and their fire apparently silenced the enemy machine guns.

Returning, the tanks pulled off the road to the south and ran into a minefield which completely wrecked one of the vehicles. Enemy fire immediately reopened in steadily increasing volume, hampering rescue of the tankers and stopping any further advance. Despite every effort to locate positions, the source of the fire was not determined by the end of the day, except that the enemy had put antitank guns somewhere in the cliffs ahead. Company E stopped to organize a night position south of and near Road Junction 2. To the right of the railroad, Company F had almost reached the coconut grove late in the afternoon, mopping up small groups of Japanese. Learning that E was digging in to the left, Company F pulled over near it to establish its night perimeter.

The 3d Battalion of the 105th had a zone that included the escarpment edging the coastal plain; therefore, its units moved northeast straddling the plain and the rough hillside. Company K, on the low ground, reached the southeast side of the coconut grove in the early afternoon, and there came under considerable fire both from the grove and from the hillside to its right. Tanks worked through the trees without finding enemy positions, and K made no further progress. It dug in for the night south of the coconut plantation, at the foot of the hill.

Just ahead of K's position, two steep sided narrow draws broke the long wall of the escarpment. On the spur between them, the cross- island road zigzagged up from Road Junction 2. A rough trail branched off this road at the edge of the plain and followed second of the two draws. It was this second draw, to be known later as Harakiri Gulch, that showed signs on 5 July of being a center of enemy resistance. Fire from the mouth of the draw had contributed to the troubles of Company K on the plain, but it was Company L (and, farther inland, the 165th Infantry) that made the real test of enemy strength in Harakiri Gulch.

Company L on 5 July faced the difficult ground on the hillside, its right flank in contact with the 3d Battalion of the 165th. Toward the middle of the morning, L had passed the first (western) gulch and was crossing the spur used by the road on its way into the upland. But when L's men reached the crest looking down into Harakiri Gulch, they were caught by heavy fire from cliff positions on the far side of the ravine. For the rest of the day, Company L was held on the spur. Despite every effort to neutralize enemy opposition by building up strong fire support, including antitank guns and artillery, any attempt at advance was stopped at the edge of Harakiri Gulch by a hail of fire. On the right, higher up the draw and beyond it, the 165th Infantry was meeting the same fierce resistance and was making no better progress. Company L dug in for the night on this spur, with I to its left rear on the hill slope.

The results of the day's action had been disappointing for the 105th Infantry. The lead units were still short of the line of departure, and, except on the right, they had not yet developed the enemy's positions. It was known in the 3d Battalion that Harakiri Gulch was strongly held, but no one yet realized how much this could affect the 105th's advance along the coastal plain below.

Plans

Plans for 6 July called for pressing the attack that had barely got under way on the previous day. The main effort was scheduled to come in the 105th's zone; failing better progress on the plain, the 165th's flank would be exposed. But at 0905 on the 6th, when the action had already begun, General Griner received orders from Corps that appeared to simplify the 27th Division's mission.

The 4th Marine Division on the right had found the going easier and was well ahead in its zone. Further unequal advance by the two divisions, along the northeast axis of attack, would expose the flank of the 4th Marine Division. Enemy resistance appeared to be heaviest toward the west coast, so that the 27th could not be expected to catch up easily. General Holland Smith decided to continue the sweep to the northeast with the 4th Marines, while the 27th Division mopped up the enemy in a more limited zone on the left flank. Division zones were therefore radically altered; the 4th Marine Division, reinforced, would extend its front to the north west, pinching out the 27th's zone beyond Makunsha, and continue toward the end of the island. All that remained for General Griner's division was to push about 2,500 yards further through hills and along the coastal plain.

Division Headquarters was optimistic about completing this job quickly. Except for the G-2, and for the company commanders who had been in contact with the enemy at Harakiri Gulch, everyone regarded the Japanese strength at that point as amounting to little more than a minor pocket. Main enemy strength was still believed concentrated farther northeast, in Paradise Valley. General Griner had been on the point of relieving the battle-weary 165th Infantry with the 106th, but now decided to let the front-line units finish the job.

By the time this new order had been received and digested by Division, the 105th Infantry was already in trouble, both on the edge of the hills and below in the plain.

More Fight on the Tanapag Plain 6 July 1944 27th Division

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