Battle of Mount Austen, the Galloping Horse, and the Sea Horse

The Battle of Mount Austen, the Galloping Horse, and the Sea Horse, part of which is sometimes called the Battle of the Gifu, took place from 15 December 1942 to 23 January 1943 and was primarily an engagement between United States and Imperial Japanese forces in the hills near the Matanikau River area on Guadalcanal during the Guadalcanal Campaign. The U.S. forces were under the overall command of Alexander Patch and the Japanese forces were under the overall command of Harukichi Hyakutake.

In the battle, U.S. soldiers and Marines, assisted by native Solomon Islanders, attacked Imperial Japanese Army (IJA) forces defending well-fortified and entrenched positions on several hills and ridges. The most prominent hills were called Mount Austen, the Galloping Horse, and the Sea Horse by the Americans. The U.S. was attempting to destroy the Japanese forces on Guadalcanal and the Japanese were trying to hold their defensive positions until reinforcements could arrive.

Both sides experienced extreme difficulties in fighting in the thick jungles and tropical environment of the battle area. Many of the American troops were also involved in their first combat operations. The Japanese were mostly cut off from resupply and suffered greatly from malnourishment and lack of medical care. After some difficulty, the U.S. succeeded in taking Mount Austen, in the process reducing a strongly defended position called the Gifu, as well as the Galloping Horse and the Sea Horse. In the meantime, the Japanese decided to abandon Guadalcanal and withdrew to the west coast of the island. From there most of the surviving Japanese troops were successfully evacuated during the first week of February 1943.

Background

Guadalcanal Campaign

Eight months after the beginning of the Pacific War, on 7 August 1942 Allied forces (primarily U.S.) landed on Guadalcanal, Tulagi, and Florida Islands in the Solomon Islands. The landings on the islands were meant to deny their use by the Japanese as bases for threatening the supply routes between the U.S. and Australia, and to secure the islands as starting points for a campaign with the eventual goal of isolating the major Japanese base at Rabaul while also supporting the Allied New Guinea campaign. The landings initiated the six-month-long Guadalcanal campaign.

The Japanese were taken by surprise. By nightfall on 8 August, the 11,000 Allied troops—primarily from the 1st Marine Division of the United States Marine Corps under the command of Lieutenant General Alexander Vandegrift— secured Tulagi and nearby small islands as well as the Japanese airfield under construction at Lunga Point on Guadalcanal. The Allies later renamed the airfield Henderson Field. Allied aircraft operating out of Henderson were called the "Cactus Air Force" (CAF) after the Allied code name for Guadalcanal. To protect the airfield, the U.S. Marines established a perimeter defense around Lunga Point. Additional reinforcements over the next two months later increased the number of U.S. troops at Lunga Point on Guadalcanal to more than 20,000.

In response to the Allied landings on Guadalcanal, the Japanese Imperial General Headquarters assigned the Imperial Japanese Army's 17th Army—a corps-sized command based at Rabaul and under the command of Lieutenant General Harukichi Hyakutake—with the task of retaking Guadalcanal. Units of the 17th Army began to arrive on Guadalcanal on 19 August to drive Allied forces from the island.

Because of the threat by CAF aircraft based at Henderson Field, the Japanese were unable to use large, slow transport ships to deliver troops and supplies to the island. Instead, the Japanese used warships based at Rabaul and the Shortland Islands to carry their forces to Guadalcanal. The Japanese warships—mainly light cruisers or destroyers from the Eighth Fleet under the command of Vice Admiral Gunichi Mikawa—were usually able to make the round trip down " The Slot" to Guadalcanal and back in a single night, thereby minimizing their exposure to CAF air attack. Delivering the troops in this manner, however, prevented most of the soldiers' heavy equipment and supplies, such as heavy artillery, vehicles, and much food and ammunition, from being carried to Guadalcanal with them. These high-speed warship runs to Guadalcanal occurred throughout the campaign and were later called the "Tokyo Express" by the Allies and "Rat Transportation" by the Japanese.

Using forces delivered to Guadalcanal in this manner, the Japanese tried three times to retake Henderson Field, but they were defeated each time. First, a reinforced battalion from the 28th Infantry Regiment was defeated in the Battle of the Tenaru on 21 August. Next, the augmented 35th Infantry Brigade was defeated in the Battle of Edson's Ridge on 12–14 September. Finally, the 2nd Infantry Division augmented by one regiment from the 38th Infantry Division was defeated with heavy losses in the Battle for Henderson Field on 23–26 October.

Throughout the campaign, the Japanese used Mount Austen (called Bear Height by the Japanese and Mount Mambulu by the local Solomon Islanders), located west of the Lunga River and about from Henderson Field, to observe the American defenses around Lunga Point. Emplaced artillery on Mount Austen delivered harassing fire on Henderson Field. The hill was also used as a defensive point to protect their positions around the upper Matanikau valley as well as to protect the Maruyama Road, which was a trail used by the Japanese to move men and supplies into the interior of the island. Mount Austen—with a summit of —was not a single peak, but a mixed ridgeline of rocky exposed and jungle-covered ridges and hilltops. After the defeat in the Battle for Henderson Field, the Army Section of Imperial General Headquarters directed Hyakutake to increase the numbers of troops and artillery emplaced on the ridgeline to help prepare for the next planned attack on the Americans. Therefore, Hyakutake directed some of the units that were retreating from the Henderson Field battle area to fortify Mount Austen and nearby hilltops. The forces deployed to Mount Austen included the 124th Infantry Regiment under Colonel Akinosuka Oka and several artillery units. Later, surviving troops from the 230th Infantry Regiment—which had taken heavy losses during the Koli Point action and subsequent retreat—joined Oka's forces around Mount Austen.

Reinforcement and resupply

On 5, 7, and 8 November, Tokyo Express missions landed most of the 38th Division's 228th Infantry Regiment and the 1st Battalion, 229th Infantry Regiment on Guadalcanal. On 10 November, Japanese destroyers landed Lieutenant General Tadayoshi Sano—commander of the 38th Infantry Division—plus his staff and 600 more troops from the 38th. Hyakutake used the newly arrived troops to help stop an American attack west of the Matanikau from 8–11 November, then sent the 228th and 229th Regiment's units on 11 November to reinforce Oka's forces. Japanese Major General Takeo Itō—commander of the 38th Division's Infantry Group—later took command of the defenses around Mount Austen.

An attempt by the Japanese to deliver the rest of the 38th Division and its heavy equipment failed during the Naval Battle of Guadalcanal on 12–15 November. Only 2,000–3,000 of the remaining 7,000 troops from the division reached the island and most of their supplies, ammunition, and equipment were lost. Because of this failure, the Japanese canceled their next planned attempt to recapture Henderson Field.

As December began, the Japanese experienced considerable difficulty in keeping their troops on Guadalcanal resupplied because of Allied air and naval attacks on the Japanese supply chain of ships and bases. The few supplies delivered to the island were not enough to sustain Japanese troops, who by 7 December 1942, were losing about 50 men each day from malnutrition, disease, and Allied ground or air attacks. The Japanese had delivered almost 30,000 army troops to Guadalcanal since the campaign began, but by December only about 20,000 of that number were still alive. Of those 20,000, about 12,000 remained more or less fit for combat duty. On 12 December, the Japanese Navy proposed that Guadalcanal be abandoned. Despite opposition from Japanese Army leaders, who still hoped that Guadalcanal could eventually be retaken from the Allies, Imperial General Headquarters, with approval from the Emperor, on 31 December, agreed to the evacuation of all Japanese forces from the island and establishment of a new line of defense for the Solomons on New Georgia. The Japanese titled the evacuation effort of their forces from Guadalcanal ''Operation Ke'' (ケ号作戦) and planned to execute the operation beginning on 14 January 1943.

In the meantime, the U.S. continued to deliver additional troops to Guadalcanal. The three infantry regiments of the U.S. Army's Americal Division, the 164th, the 182nd and the 132nd, were delivered to Guadalcanal on 13 October, 12 November, and 8 December, respectively. In addition, the U.S. Army's independent 147th Infantry Regiment plus the 2nd Marine Division's 8th Marine Regiment landed on 4 November. The reinforcements also included additional artillery, construction, aviation, naval, and support units.

On 9 December, U.S. Army Major General Alexander Patch—commanding general of the Americal Division—succeeded Vandegrift as commander of Allied forces on Guadalcanal and Tulagi. That same day, the 5th Marine Regiment departed the island, followed by the rest of the 1st Marine Division by the end of the month. Patch was ordered to eliminate all Japanese forces remaining on Guadalcanal. Patch told his superior—Millard Harmon, who commanded all U.S. Army forces in the South Pacific—that he needed more troops to accomplish his mission. In response, Harmon ordered the 25th Infantry Division—which was in the process of relocating from Hawaii to the South Pacific area—to ship directly to Guadalcanal. The 25th's units would arrive at Guadalcanal in stages during the last two weeks of December and the first week of January 1943. In addition, the rest of the 2nd Marine Division's units—including the 6th Marine Regiment—were ordered to Guadalcanal during the same time period. By 7 January, American forces on Guadalcanal would total just over 50,000 men.

Battles

First Battle of Mount Austen

On 12 December 1942, a small group of Japanese soldiers from the 38th Field Engineer Regiment successfully infiltrated the American lines from the south, destroying a fighter aircraft and a fuel truck on Henderson Field before escaping back to friendly lines. Two days later, a U.S. Army patrol from the 132nd Infantry Regiment skirmished with a group of Japanese on the eastern slopes of Mount Austen. On 15 December, in yet another night infiltration raid onto Henderson Field, a Lieutenant Ono led four men equipped with picric acid blocks past American sentry positions destroying several P-39 Airacobra fighters. Throughout the Guadalcanal campaign, Japanese forces would continue night infiltration tactics against U.S. forces, but causing few American casualties.

General Patch, however, was convinced that these events illustrated an unacceptable risk to Henderson Field by Japanese troops stationed on and around nearby Mount Austen. Thus, on 16 December, in preparation for a planned general offensive to try to destroy all Japanese forces remaining on Guadalcanal, Patch elected to first secure the Mount Austen area. He therefore ordered the 132nd Infantry Regiment to immediately seize the objective. While the 132nd Infantry Regiment had little modern combat experience aside from jungle skirmishes and patrols, it was proud of its combat history, having participated in both the Civil War and World War I, and its young reserve officers and NCOs considered themselves skilled in rifle and machinegun tactics and marksmanship.

The 132nd's commander—Colonel Leroy E. Nelson—directed his 3rd Battalion to lead the American assault on the first of several hills, followed by the regiment's 1st Battalion. Artillery support was provided by 105 mm howitzers from the U.S. Army's 246th Field Artillery Battalion and the 75 mm pack howitzers of the 2nd Battalion 10th Marines.

The exposed hills making up the Mount Austen complex were arbitrarily numbered by the Americans for reference purposes (see map at right). On 17 December, Nelson's 3rd Battalion—commanded by Lieutenant Colonel William C. Wright—advanced south of Hill 35 and began to climb toward Mount Austen's summit near Hills 20 and 21. In order to achieve its timetable set by the division commander, the battalion was forced to leave behind many of its support weapons, such as heavy mortars and machine guns, and to take only limited quantities of ammunition and supplies, all of which had to be hand-carried along hacked-out paths through thick jungle. At 09:30 on 18 December, as Wright's lead elements approached, Japanese defenders pinned down the Americans with machine-gun and rifle fire. Exhausted and dehydrated by their trek through the thick jungle, Wright's troops—unable to deploy quickly out of column formation—made no headway against the Japanese defenses.

The next morning, after an artillery barrage and air strike from the CAF, Wright went forward with several artillery observers to investigate the terrain in front of his forces. Using concealed fire lanes, a Japanese machine-gun team killed Wright with a burst of fire at 09:30. Wright's second in command, Major Louis Franco, was unable to get forward and take command until late in the day, preventing the battalion from continuing the attack. At the same time, Japanese riflemen infiltrated the American positions and effectively harassed the command posts of both the 3rd and 1st Battalions as well as the column of heavily loaded American supply and engineer parties on the hacked-out jungle trail linking the battalions with the Lunga perimeter. Both U.S. battalions dug in for the night while artillery bombarded the Japanese positions.

Between 20 and 23 December, the Japanese apparently withdrew from the area, as aggressive U.S. Army patrols encountered no more enemy in the area of Hills 20 and 21 and further to the south. Nelson ordered the two battalions to move west to Hill 31 and then attack south towards Hill 27. On 24 December, the 3rd Battalion was halted on the slopes of Hill 31 by intense machine-gun fire from well-concealed positions.

Facing the Americans was the most strongly fortified Japanese position on Guadalcanal, nicknamed "the Gifu" (after Gifu Prefecture in Japan) by the Japanese. The Gifu position sat between the summits of Mount Austen and Hills 27 and 31 and consisted of a line of 45–50 interconnected, mutually supporting, well-camouflaged pillboxes dug into the ground and forming a horseshoe shape with the open end to the west. Only about of each pillbox was above ground with walls and roofs, constructed from logs and dirt, up to thick. Each pillbox contained one to two machine-guns and several riflemen; some were sited underneath huge jungle trees. Each of these pillbox emplacements was sited to provide mutual support to the others. Numerous foxholes and trenches provided additional support and cover for additional riflemen and machine-gunners. Behind the pillboxes, the Japanese had sited 81 mm and long-range 90mm mortars. The Gifu was commanded by Major Takeyoshi Inagaki with around 800 men from the 2nd Battalion, 228th Regiment and the 2nd Battalion, 124th Infantry.

Between 25 and 29 December, the Japanese defenders prevented the Americans from making any headway in their attempt to overrun the Gifu position. While the U.S. 3rd Battalion—with artillery support—conducted frontal attacks against the position to pin the defenders, the U.S. 1st Battalion attempted to flank the Gifu on the east. However, as the Japanese defenses were fully integrated, the flanking attempt was unsuccessful. By 29 December, U.S. losses had reached 53 killed, 129 wounded, and 131 sick, though morale remained high. Assisting the Americans in this battle were Fijian commandos led by officers and non-commissioned officers from the New Zealand Expeditionary Force.

On 2 January, Nelson added his 2nd Battalion—commanded by Lieutenant Colonel George F. Ferry—to the offensive and sent them on a march around the Gifu toward Hill 27. The battalion reached the lower slopes of the hill by 16:00 without meeting serious resistance from the Japanese. This same day, Nelson—who was physically and mentally exhausted and may have been suffering from malaria—was replaced as commander of the 132nd by Lieutenant Colonel Alexander M. George.Frank, pp. 532–533, 750; Miller, pp. 237–238, 246–249; Jersey, p. 359; Griffith, p. 266 Sources are unclear whether he requested his own relief or was ordered to relinquish command.

The next day, elements of the 132nd's 2nd Battalion occupied the summit of Hill 27, surprised and killed a Japanese 75 mm artillery crew, and successfully repulsed, with help from heavy artillery fire, six Japanese counterattacks on their positions. By this time, the soldiers atop Hill 27 were running extremely short of ammunition and grenades, with Japanese forces returning ten shots to each one fired by the Americans, and medical supplies were exhausted. The 2nd's efforts to improve its position were made more difficult by the hard coral underneath the hill's sod, which made the digging of foxholes difficult. The remainder of the 2nd Battalion, carrying ammunition, food, and medical supplies, reached Hill 27 and joined the battle, where they soon gained combat superiority over the attacking Japanese. At the same time, with the infusion of new leadership by Lieutenant Colonel George, the 1st and 3rd Battalions attacked and pushed a short way into the Gifu, killing 25 Japanese in the process, then closed the gaps between their units and consolidated their positions, while killing many of the Japanese defenders. One officer from the 2nd Battalion—who had brought his personal sniper rifle to the battle—witnessed the final disintegration of Japanese units attacking Hill 27 with a final flurry of suicidal frontal charges. The Japanese soldiers in the Gifu, who had apparently not been resupplied or replenished during the battle, consumed their last remaining food rations on 1 January.

Since the beginning of its offensive on Mount Austen, the 132nd had lost 115 killed and 272 wounded. The relatively high number of combat deaths were caused in part by wound infections in the tropical conditions and inability to evacuate men wounded in the early stages of the operation. Even after intervention by the 2nd Battalion, wounded men continued to die, unable to withstand the arduous and slippery portage back down improvised jungle trails on a stretcher carried by two men. These losses, plus the effects of tropical diseases, heat, and combat exhaustion, temporarily rendered the 132nd's 1st and 3rd Battalions incapable of further offensive action. Thus, on 4 January, the 1st and 3rd Battalions were ordered to dig in and hold positions surrounding the Gifu on the north, east, and south.

Reviewing the first Mount Austen offensive, former Marine officer and historian Samuel B. Griffith concluded, "As the thoroughly butchered Mount Austen operation dragged on into January, it became apparent that both Major General Patch and his assistant Division commander rigadier_General_rigadier_General_Edmund_Sebree">Edmund_Sebree.html"_;"title="rigadier_General_Edmund_Sebree">rigadier_General_Edmund_Sebreehad_much_to_unlearn,_and_perhaps_even_more_to_learn."_However,_while_Patch's_decision_to_attack_Mount_Austen_was_criticized,_one_participant_noted_the_difficulties_faced_by_the_132nd_Regiment_and_its_commanders,_including_the_terrain,_limited_equipment_(light_mortars_and_machineguns_with_limited_ammunition_supply,_no_flamethrowers_or_pole_charges),_and_the_necessity_of_assaulting_thoroughly_integrated,_prepared,_and_roofed-over_Japanese_defenses,_which_resisted_direct_hits_by_75 mm_and_in_some_cases_105 mm_shells.

For_its_part,_once_the_132nd_was_able_to_treat_its_wounded,_morale_remained_high_in_the_newly_blooded_regiment,_which_played_a_significant_role_in_later_combat_operations_on_Guadalcanal._The_2nd_Battalion,_with_just_27_killed,_was_immediately_assigned_to_further_offensive_combat_operations.

Losses_among_the_Gifu_defenders_are_unknown,_but_were_estimated_by_one_2nd_Battalion_officer_as_of_9 January_1943_at_500_killed_and_wounded;_most_of_the_latter_would_later_die_of_their_wounds_when_combined_with_illness_and_starvation._A_Japanese_officer's_recovered_diary_stated_that_the_Japanese_had_suffered_heavy_casualties._Japanese_prisoners_captured_in_later_operations_referred_to_the_combat_at_Hills_27_and_31_as_''The_Battle_of_the_Mountain_of_Blood''.

_Arrival_of_American_reinforcements

On_2_January,_with_the_arrival_of_the_U.S._Army's_25th_Division_and_the_rest_of_the_U.S._Marine_2nd_Division,_all_of_the_American_units_on_Guadalcanal_and_Tulagi_were_together_designated_as_the_ rigadier_General_Edmund_Sebree">Edmund_Sebree.html"_;"title="rigadier_General_Edmund_Sebree">rigadier_General_Edmund_Sebreehad_much_to_unlearn,_and_perhaps_even_more_to_learn."_However,_while_Patch's_decision_to_attack_Mount_Austen_was_criticized,_one_participant_noted_the_difficulties_faced_by_the_132nd_Regiment_and_its_commanders,_including_the_terrain,_limited_equipment_(light_mortars_and_machineguns_with_limited_ammunition_supply,_no_flamethrowers_or_pole_charges),_and_the_necessity_of_assaulting_thoroughly_integrated,_prepared,_and_roofed-over_Japanese_defenses,_which_resisted_direct_hits_by_75 mm_and_in_some_cases_105 mm_shells.

For_its_part,_once_the_132nd_was_able_to_treat_its_wounded,_morale_remained_high_in_the_newly_blooded_regiment,_which_played_a_significant_role_in_later_combat_operations_on_Guadalcanal._The_2nd_Battalion,_with_just_27_killed,_was_immediately_assigned_to_further_offensive_combat_operations.

Losses_among_the_Gifu_defenders_are_unknown,_but_were_estimated_by_one_2nd_Battalion_officer_as_of_9 January_1943_at_500_killed_and_wounded;_most_of_the_latter_would_later_die_of_their_wounds_when_combined_with_illness_and_starvation._A_Japanese_officer's_recovered_diary_stated_that_the_Japanese_had_suffered_heavy_casualties._Japanese_prisoners_captured_in_later_operations_referred_to_the_combat_at_Hills_27_and_31_as_''The_Battle_of_the_Mountain_of_Blood''.

_Arrival_of_American_reinforcements

On_2_January,_with_the_arrival_of_the_U.S._Army's_25th_Division_and_the_rest_of_the_U.S._Marine_2nd_Division,_all_of_the_American_units_on_Guadalcanal_and_Tulagi_were_together_designated_as_the_XIV_Corps_(United_States)">XIV_Corps_14_Corps,_14th_Corps,_Fourteenth_Corps,_or_XIV_Corps_may_refer_to:

*__XIV_Corps_(Grande_Armée),_a_unit_of_the_Imperial_French_Army_during_the_Napoleonic_Wars
*_XIV_Corps_(German_Empire),_a_unit_of_the_Imperial_German_Army_prior_to_and_during_World_...
_with_Patch_in_command._Sebree_took_over_as_commander_of_the_Americal_Division._On_5 January,_Patch_issued_his_plan_to_begin_operations_to_clear_Guadalcanal_of_Japanese_forces._The_2nd_Marine_Division_was_to_push_westward_from_the_Matanikau_River_along_the_coast_while_the_25th_Division_was_to_finish_clearing_Mount_Austen_and_to_secure_the_hilltops_and_ridges_located_around_the_inland_forks_of_the_Matanikau._The_Americal_Division_and_the_147th_Infantry_Regiment_(United_States).html" ;"title="XIV_Corps_(United_States).html" "title="Edmund_Sebree.html" ;"title="Edmund_Sebree.html" ;"title="rigadier General Edmund Sebree">rigadier General Edmund Sebree">Edmund_Sebree.html" ;"title="rigadier General Edmund Sebree">rigadier General Edmund Sebreehad much to unlearn, and perhaps even more to learn." However, while Patch's decision to attack Mount Austen was criticized, one participant noted the difficulties faced by the 132nd Regiment and its commanders, including the terrain, limited equipment (light mortars and machineguns with limited ammunition supply, no flamethrowers or pole charges), and the necessity of assaulting thoroughly integrated, prepared, and roofed-over Japanese defenses, which resisted direct hits by 75 mm and in some cases 105 mm shells.

For its part, once the 132nd was able to treat its wounded, morale remained high in the newly blooded regiment, which played a significant role in later combat operations on Guadalcanal. The 2nd Battalion, with just 27 killed, was immediately assigned to further offensive combat operations.

Losses among the Gifu defenders are unknown, but were estimated by one 2nd Battalion officer as of 9 January 1943 at 500 killed and wounded; most of the latter would later die of their wounds when combined with illness and starvation. A Japanese officer's recovered diary stated that the Japanese had suffered heavy casualties. Japanese prisoners captured in later operations referred to the combat at Hills 27 and 31 as ''The Battle of the Mountain of Blood''.

Arrival of American reinforcements

On 2 January, with the arrival of the U.S. Army's 25th Division and the rest of the U.S. Marine 2nd Division, all of the American units on Guadalcanal and Tulagi were together designated as the XIV Corps (United States)">XIV Corps