Very irregularly shaped and characterized by rough, mountainous terrain of volcanic origin, the Bicol Peninsula stretches southeast from Atimonan on the Lamon Bay shore of the Bondoc Isthmus nearly 170 miles to the tip of the subsidiary Sorsogon Peninsula, Luzon’s most southerly extension. The best route of communication in prewar days was a branch of the Manila Railroad that wound its way through the peninsula to Legaspi, forty miles northwest of the Sorsogon Peninsula’s tip. The railroad, however, had been unusable at least since December 1944, when Allied Air Forces planes from Leyte had begun to knock out bridges and destroy rolling stock. Guerrillas had lent a hand to the work of destruction, and had also conducted sabotage operations along Route 1, likewise leading southeast into the Bicol Peninsula from Atimonan. Paved only through a few towns before the war, Route 1 was a two-lane, gravel road over most of its distance. In some of the more rugged parts of the peninsula the highway, which the Japanese had not maintained any too well, narrowed to one lane of gravel or dirt and was subject to washouts and landslides.
The southern shores of the Sorsogon Peninsula form the northern side of San Bernardino Strait. Therefore, Sixth Army and Allied Naval Forces planners gave consideration to proposals to land the 158th RCT directly on that peninsula, but soon found that the region had few good landing sites, lacked protected anchorages, and had poor overland communications. On the other hand Legaspi Port, on the shores of Albay Gulf two miles east of Legaspi, had good landing beaches, the best port facilities in the Bicol area, and offered access to overland routes to both the Sorsogon Peninsula and the rest of the Bicol Peninsula. Moreover, Albay Gulf provided a large protected anchorage area. Finally, quick seizure of the Legaspi-Legaspi Port area would give the 158th RCT an excellent chance to cut off Japanese forces on the Sorsogon Peninsula and prevent other Japanese from withdrawing into that peninsula in an attempt to maintain control over San Bernardino Strait.
A landing at Legaspi Port, however, would pose certain problems. Sixth Army’s G-2 Section estimated that 1,500 to 2,000 Japanese held strong beach defenses, including heavy artillery, in the Legaspi area or were so deployed as to be within easy striking distance of the shores of Albay Gulf. Intelligence officers also believed that the Japanese maintained mine fields in Albay Gulf and San Bernardino Strait and that other Japanese manned coast defense guns on the Sorsogon Peninsula in order to control the strait, the shortest water route to Albay Gulf from the 158th RCT’s staging area in southern Luzon.
The necessity for mine sweeping Albay Gulf and San Bernardino Strait, as well as that for intensive preassault aerial bombardment along the Albay Gulf beaches, had as much influence on General Krueger’s decision to postpone the landing at Legaspi Port as had the necessity for moving the 1st Cavalry Division into southern Luzon before taking the 158th RCT out. Moreover, the bulk of the naval resources in the Pacific was committed to the Central Pacific Area’s invasion of the Ryukyu Islands, beginning in late March; to the support of Eighth Army operations in the southern Philippines, now picking up momentum; and to the supply and reinforcement runs to Luzon. Scant naval means were left over to stage the Bicol Peninsula operation–the Allied Naval Forces had no heavy bombardment ships, nor could the Allied Naval Forces redeploy the necessary mine sweepers from the southern Philippines in time to meet Krueger’s initial target date for the Legaspi assault, 25 March. The task of reducing the Albay Gulf beach defenses devolved upon the Fifth Air Force, but with its other commitments, the Fifth Air Force could not begin large-scale bombardment at Albay Gulf until 23 March.
Allied Naval Forces planners pointed out that a two-day aerial bombardment would be inadequate to assure destruction of known and suspected beach defenses. Unable to face with aplomb the prospect of staging an amphibious assault against defended beaches in the mined and restricted waters of Albay Gulf, the Allied Naval Forces insisted that the Fifth Air Force be given time to obliterate the defenses. Having little choice in the face of all these problems, General Krueger finally set the date for the Legaspi assault at 1 April.
The 158th RCT would stage at Balayan Bay–some cargo and a few attached units would load at Subic Bay–and sail eastward aboard the vessels of Task Group 78.4, Capt. Homer F. McGee, USN, commanding. The first wave would go ashore in LCVP’s, but so few of these craft were available that the 158th RCT would be able to land only two companies abreast in the initial assault. Planners did not think it too risky to send such a small force shoreward, for they expected that the preliminary air and naval bombardment of the beaches would have driven most of the Japanese three to four miles inland. The Japanese, even if so inclined, would probably be unable to organize a counterattack before the rest of the 158th RCT had landed by LCI, LSM, and LST.
Upon assembling ashore, the 1st Battalion, 158th Infantry, would secure the beachhead area, clear the town of Legaspi, and capture a small airstrip a mile north of the town. The 2d Battalion would make ready to swing south and southeast into the Sorsogon Peninsula; the 3d Battalion would be in reserve. After securing the beachhead and the Sorsogon Peninsula, the 158th RCT, upon orders from Sixth Army, would strike northwestward up the Bicol Peninsula to gain contact with XIV Corps, which would be moving southeast into the peninsula from southern Luzon. The Sixth Army’s task of clearing the northern side of the Visayan Passages would then be completed.
Sixth Army’s estimate that the Japanese had over 1,500 troops in the Legaspi area was quite accurate. The Japanese garrison there included about 1,000 naval troops of the 35th Naval Guard Unit, among whom some 500 men could be counted as trained combat effectives, and 600-700 Japanese Army troops, comprising a reinforced company of the 26th Independent Mixed Regimentand elements of various 4th Air Army ground service units. Around 500 more Japanese, including about 175 Formosan labor troops and some stragglers from Samar, were on the Sorsogon Peninsula. The remaining 1,400 Japanese on the Bicol Peninsula, distributed among three concentrations far northwest of Legaspi, were almost all from the 4th Air Army. Japanese command on the peninsula was divided. The 35th Naval Guard Unit reported to Headquarters, 33d Naval Special Base Force, on Cebu Island; the Army troops were ostensibly under the direct control ofShimbu Group headquarters, but by 1 April were out of contact with that headquarters.
The Japanese on the Bicol Peninsula were not interested in the defense of the northern shores of the Visayan Passages, and the 4th Air Army troops on the Sorsogon Peninsula had no intention of denying San Bernardino Strait to Allied shipping. The earlier task of the air force units had been to maintain an airstrip that the Allied Air Forces had long since put out of action. Now the principal mission of all Japanese on the Bicol Peninsula was to deny Sixth Army the use of that peninsula as a route of advance against the rear of Shimbu Group’s main body of troops.
The Japanese had established two defensive lines in the Legaspi area. They anchored the first (easterly) line on the south at Mt. Bariway, 2 miles southwest of Legaspi, extending the line north 4 miles along a low ridge to barrio Busay, 3 miles northwest of Legaspi. Busay lay on Route 164, the connecting link between Legaspi Port and Route 1 at Camalig, 6 miles northwest of Legaspi. The 35th Naval Guard Unit defended the second line, which lay in rough, densely jungled ground along the Cituinan Hills south and southeast of Camalig. These hills controlled the approaches to Camalig via Route 164, from the east, and via Route 1 from the south and west.
Task Group 78.4 moved through San Bernardino Strait and into Albay Gulf on 1 April without incident. The only opposition to the 158th Infantry’s landing at Legaspi Port was a few rounds of artillery fire from a weapon that a destroyer quickly put out of action. Hitting the beach about 1000, the 158th Infantry secured Legaspi Port, Legaspi, and the airstrip north of Legaspi by 1300, finding no Japanese. In the late afternoon troops moved on to Daraga, a mile and a half northwest of Legaspi, and then advanced southward along a secondary road leading to Route 1. About 800 yards south of Daraga Japanese machine gun fire from the Mt. Bariway-Busay Ridge pinned down the 158th’s leading company, and during the following night Japanese infantry surrounded the unit. The next morning,with the aid of a diversionary attack staged by other elements of the 158th Infantry, the beleaguered company fell back east of Daraga. Meanwhile, patrols had uncovered more Japanese defenses on the ridge line northwest of Daraga. The 158th Infantry had gained firm contact with the Japanese first line of defense.
The 158th RCT was now in a bit of a dilemma. Under orders to clear the Sorsogon Peninsula as quickly as possible, the RCT had found the only overland means of access to that objective, Route 1, blocked by the Japanese defenses south and southwest of Daraga. The RCT would either have to drive off the Japanese there, or it would have to move troops to the Sorsogon Peninsula in a shore-to-shore operation. Brig. Gen. Hartford MacNider, commanding the 158th RCT, could not choose the latter course at this time. First, so few landing craft were available to him that to divert any from general unloading to move even a battalion to the Sorsogon Peninsula might very well create insoluble logistical problems at the Legaspi beachhead. Second, Task Group 78.4 had found no signs of Japanese along the southern shores of the Sorsogon Peninsula as the task group had transited San Bernardino Strait. Third, Eighth Army had already cleared the southern shores of the strait. MacNider therefore felt that he could safely postpone his advance into the Sorsogon Peninsula until such time as the 158th Infantry could use the overland route. Finally, lacking precise information on the strength and extent of the Japanese defenses in the Daraga area, MacNider was loath to divert much strength to the Sorsogon Peninsula. The 158th Infantry, having only 2,000 combat effectives, was some 900 men under authorized strength.
From 2 through 10 April the 158th Infantry fought hard in rough, jungled terrain to overcome the resistance in the Daraga region, the regiment losing 45 men killed and 200 wounded, the Japanese over 500 killed. The battle took considerably longer than General MacNider had anticipated and threatened to cause an undue delay in the occupation of the Sorsogon Peninsula. Therefore, on 6 April, deciding he could wait no longer, he had loaded the Antitank Company, 158th Infantry, on five LCM’s of the 592d Engineer Boat and Shore Regiment and had dispatched it to Bacon, on the north shore of the peninsula. Landing against no opposition, the Antitank Company quickly secured Bacon and the Philippine terminus of the transpacific cable, and then moved on southwest five miles to occupy the town of Sorsogon against no resistance.
By 9 April patrols had discovered that most of the Japanese on the Sorsogon Peninsula had concentrated in low hills north of Bulan, on the peninsula’s southwestern coast. Of insufficient strength to attack this Japanese concentration, the Antitank Company continued patrolling until the 2d Battalion, 158th Infantry, after an unopposed motor march along Route 1 from Daraga, reached Bulan on 12 April. Supported by a 105-mm. howitzer battery of the 147th Field Artillery and by Fifth Air Force planes, the reinforced 2d Battalion broke up the Japanese concentration near Bulan by 16 April at the cost of only 6 men wounded. The battalion, which returned to Daraga on the 18th, had killed or found dead over 150 Japanesein the Bulan region, and had accepted the willing surrender of 155 Formosan labor troops. Guerrillas took over the task of mopping up.
Clearing the Bicol Peninsula
The 158th RCT, acting upon new instructions from Sixth Army, turned its energies to clearing the rest of the Bicol Peninsula and to gaining contact with XIV Corps, which Sixth Army had directed to start driving into the peninsula from southern Luzon. Without waiting for the 2d Battalion to return from the Sorsogon Peninsula, the remainder of the 158th RCT, on 11 April had struck toward Camalig from Daraga, employing Routes 1 and 164 as axes of advance. Troops along Route 164 bypassed the Japanese defenses at the Cituinan Hills to the north and entered Camalig unopposed on the afternoon of the 11th.
Since the Japanese in the Cituinan Hills posed a threat to the 158th RCT’s line of communication back to Legaspi, General MacNider felt that an advance in strength beyond Camalig before reducing the Cituinan defenses would overreach the bounds of a calculated risk. Accordingly, on 12 April, the 1st and 3d Battalions, 158th Infantry, attacked into the hills. Slowed by thick jungle and rough terrain almost as much as by the Japanese, and constantly harassed by night attacks, the two battalions had not overrun the defenses when, on 19 April, the 2d Battalion returned from the Sorsogon Peninsula to join the fight. Progress continued to be painfully slow, and it was not until 28 April that organized Japanese resistance finally collapsed. The task of clearing the Cituinan Hills cost the 158th Infantry approximately 40 men killed and 235 wounded; the Japanese lost almost 700 men killed in the region.
Although the 158th RCT did not know it, the reduction of the Cituinan Hills marked the end of large-scale organized resistance on the Bicol Peninsula, where no more than 1,400 Japanese remained alive as of the end of April. On the 29th the main body of the 158th began moving northwestward from Camalig, following a reinforced company that had reached Iraga, twenty-five miles distant, on 14 April. Rapidly, the regiment overran potentially strong enemy positions in excellent defensive terrain as the remaining Japanese, demoralized, offered only token resistance before melting away into hills on either side of Route 1. On 2 May patrols of the 158th Infantry established contact with the 5th Cavalry at barrio San Agustin, on Route 1 fifteen miles northwest of Iraga.
Troops of the 1st Cavalry Division had begun moving onto the Bicol Peninsula on 12 April, when they relieved units of the 11th Airborne Division at Atimonan. The next day the 5th Cavalry struck east from Atimonan and on the 14th reached Calauag, thirty miles away. All the way from Atimonan to Calauag, Route 1 was in poor condition and beyond Calauag supply movements were almost impossible. The speed of advance now hinged on the speed of engineer road and bridge repairs. Accordingly, the 5th Cavalry secured the eastern shore of Tayabas Bay and set up a supply point at the bay’s northeastern corner so that LCM’s could bring forward ammunition, food, and equipment from Batangas. Beginning on 27 April the main body of the regiment began moving by LCM across Ragay Gulf, the first indentation on the south coast of the Bicol Peninsula beyond Tayabas Bay. On the 28th the regiment, encountering no resistance, moved from the shores of Ragay Gulf to Naga, eight miles northwest of barrio San Agustin, and had no trouble marching south to meet the 158th Infantry.
Guerrillas had informed XIV Corps, which acquired control of the 158th RCT on 22 April, that a Japanese force of some 2,500 men was dug in along the slopes of Mt. Isarog, an extinct volcano centering eight miles northeast of San Agustin. This report the 5th Cavalry and 158th Infantry proved false in a series of patrol actions between 2 and 15 May. The next day, the 16th, General MacNider radioed to General Griswold that the Bicol Peninsula was secure and that no signs of organized Japanese resistance remained.
The two regiments continued patrolling for some weeks until, on 6 June, the 5th Cavalry returned to southern Luzon. The 158th RCT busied itself with the problem of reorganizing and equipping guerrilla forces and in mid-June turned over responsibility for further mopping up to the Filipinos. To that time the operations to clear the Bicol Peninsula had cost the U.S. Army units involved approximately 95 men killed and 475 wounded. The Japanese had lost over 2,800 killed and 565 captured, including 350 Formosan labor troops whom the Japanese Army had left to fend for themselves.
The strategic goal of the Bicol Peninsula operation–to finish clearing the Visayan Passages–had been realized on 2 May with the contact between the 158th Infantry and the 5th Cavalry at San Agustin. The final patrolling and mopping up the two regiments undertook had provided the necessary capstones to the combined Sixth Army-Eighth Army campaign to assure the safety of the Visayan Passages for Allied shipping.
Undertaken against generally ill-equipped, poorly fed, second-class and third-class Japanese forces, the campaign had yet proved costly. U.S. Army units involved had lost roughly 300 men killed and 1,130 wounded; the Japanese, to mid-June, had lost at least 8,125 killed and nearly 750 captured. The campaign had proved logistically more important than it had strategically or tactically. Sixth Army, Eighth Army, and Allied Naval Forces had not found the Japanese coast artillery and mine fields they had expected to discover emplaced so as to endanger Allied shipping in the passages. Nevertheless, General MacArthur would ultimately have had to direct his subordinate echelons to eliminate the Japanese from southern Luzon, the Bicol Peninsula, northern Samar, and the islands of the inner passages if for no other reason than to liberate from the Japanese yoke the many thousands of Filipino inhabitants of those regions and to restore to the Filipinos their lawful government…