Mortars and artillery dueled from each side. The Japanese would creep right next to the Marine positions for safety. Marines had to call friendly fire almost into their laps. On the narrow trail, men often had to expose themselves. The Japanese got the worst of it, for suddenly, shortly after noon on 9 November the enemy resistance crumbled. By 1500, the junction of the Piva and Numa-Numa trails was reached and secured. Some 550 Japanese died. There were 19 Marines dead and 32 wounded.
Adm William F. Halsey (pith helmet) and MajGen Geiger (“fore and aft” cover) watch Army reinforcements come ashore at Bougainville.
National Archives Photo 127-N-65494
To consolidate the hard-won position, Marine torpedo bombers from Munda blasted the surrounding area on 10 November. This allowed two battalions of the 9th Marines to settle into good defensive positions along the Numa-Numa Trail with, as usual, “aggressive” patrols immediately fanning out. The battle for the Piva Trail had ended victoriously.
The key logistical element in this engagement—and nearly all others on Bougainville—was the amtrac. There were vast areas where tanks and half-tracks, much less trucks, simply could not negotiate the bottomless swamps, omnipresent streams, and viscous mud from the daily rains. The amtracs proved amazingly flexible; they moved men, ammunition, rations, water, barbed wire, and even radio jeeps to the front lines where they were most needed. Heading back, they evacuated the wounded to reach the desperately needed medical centers in the rear.
Department of Defense Photo (USMC) 65162
A bloody encounter on 14 November at the junction of the Numa-Numa and Piva Trails: Marine infantrymen had been stopped by well dug-in and camouflaged enemy troops. Five Marine tanks rushed up and attacked on a 250-yard front through the jungle.
Other developments came at this juncture in the campaign. As noted, the 37th Infantry Division was fed into the perimeter. At the top of the command echelon Major General Roy S. Geiger relieved Vandegrift as Commanding General, IMAC, on 9 November and took charge of Marine and Army units in the campaign from an advanced command post on Bougainville.