Following the capture of Hellzapoppin Ridge, the Marines began sending patrols to the east over the Eagle River towards the Torokina.
These lasted for three days and penetrated far behind the Japanese lines, but they did not prove fruitful for the Marines, resulting in no contact to offset the hardships faced in coming to grips with the terrain.
Japanese activity during this time was limited to artillery barrages that were brought down largely on the US supply dumps that were located to the southwest around Evansville and which, as a consequence, resulted in only a few casualties.

Contact between the two forces was reestablished on 21 December when a Marine patrol was engaged by a force of 14–18 Japanese around Hill 600A. Breaking contact, the patrol returned to US lines where the situation was reported and subsequently a detachment from the 2nd Battalion, 21st Marines was detailed with returning to the location and putting in an attack that afternoon.
The attack went in at 15:45 and for the loss of one man killed and another wounded they were successful in wresting control of the hill from Japanese, who then retired from the position.
As the detachment was too small to hold the position against a Japanese counterattack if one was launched, the Marines returned to their main defensive position before the light failed and reported the situation to the 3rd Division command post.

Upon receipt of the report, Turnage decided to establish a platoon-sized outpost on the hill and the following morning a force from the 3rd Battalion, 21st Marines, which included heavy weapons support and an artillery forward observer, was sent out to occupy it.
The Japanese, however, had returned during the night following the battle and had retaken the position and established themselves firmly.
Heavy fire prevented the Marines from advancing and forced them to call back to regimental headquarters for reinforcements.

Company 'I' was sent up, and its commander, misreading the situation and thinking that the Japanese held the crest of the ridge, rather than the foot of its reverse slope, ordered a three-pronged "double envelopment" maneuver, utilizing two elements of his force to flank while the third attacked frontally.
With almost no appreciation of the situation or the terrain, the maneuvering elements turned-in to affect the envelopment too soon and consequently moved into the flanks of the platoon that was in contact, rather than the Japanese emplacements.
Consequently, they too began to take heavy fire and as a result, the American company commander gave the order to withdraw so that an artillery strike could be called down on the Japanese.
This too proved to be unsuccessful in forcing the Japanese from the hill and Company 'I' returned to the main defensive position before sunset.

The following day, 23 December, Company 'K' from the 3rd Battalion, 21st Marines, renewed the attack with a heavy-weapons platoon attached to provide support by fire.
Forming up for an attack further south from where Company 'I' had attacked the day before, one platoon was sent on a reconnaissance along a steep, narrow ridge.
Receiving heavy fire, it was forced to fall back and artillery was called in.
This had only limited results due to tree bursts; nevertheless, half an hour later, a second platoon was thrown in and this too was turned back by stiff resistance.

Once again indirect fire support was called in, this time lasting only ten minutes but augmented by mortar fires, after which a flanking attack was attempted.
This proved unsuccessful and as night fell, Company 'K' withdrew.
The next day, however, Marine patrols found that the Japanese had abandoned the position during the night.
Four Marines had been killed and eight wounded in taking the position; only one Japanese body was found when the position was searched later.
Following the capture of Hellzapoppin Ridge, the Marines began sending patrols to the east over the Eagle River towards the Torokina. These lasted for three days and penetrated far behind the Japanese lines, but they did not prove fruitful for the Marines, resulting in no contact to offset the hardships faced in coming to grips with the terrain. Japanese activity during this time was limited to artillery barrages that were brought down largely on the US supply dumps that were located to the southwest around Evansville and which, as a consequence, resulted in only a few casualties.
Contact between the two forces was reestablished on 21 December when a Marine patrol was engaged by a force of 14–18 Japanese around Hill 600A. Breaking contact, the patrol returned to US lines where the situation was reported and subsequently a detachment from the 2nd Battalion, 21st Marines was detailed with returning to the location and putting in an attack that afternoon. The attack went in at 15:45 and for the loss of one man killed and another wounded they were successful in wresting control of the hill from Japanese, who then retired from the position. As the detachment was too small to hold the position against a Japanese counterattack if one was launched, the Marines returned to their main defensive position before the light failed and reported the situation to the 3rd Division command post.
Upon receipt of the report, Turnage decided to establish a platoon-sized outpost on the hill and the following morning a force from the 3rd Battalion, 21st Marines, which included heavy weapons support and an artillery forward observer, was sent out to occupy it. The Japanese, however, had returned during the night following the battle and had retaken the position and established themselves firmly. Heavy fire prevented the Marines from advancing and forced them to call back to regimental headquarters for reinforcements.
Company 'I' was sent up, and its commander, misreading the situation and thinking that the Japanese held the crest of the ridge, rather than the foot of its reverse slope, ordered a three-pronged "double envelopment" maneuver, utilizing two elements of his force to flank while the third attacked frontally. With almost no appreciation of the situation or the terrain, the maneuvering elements turned-in to affect the envelopment too soon and consequently moved into the flanks of the platoon that was in contact, rather than the Japanese emplacements. Consequently, they too began to take heavy fire and as a result, the American company commander gave the order to withdraw so that an artillery strike could be called down on the Japanese. This too proved to be unsuccessful in forcing the Japanese from the hill and Company 'I' returned to the main defensive position before sunset.
The following day, 23 December, Company 'K' from the 3rd Battalion, 21st Marines, renewed the attack with a heavy-weapons platoon attached to provide support by fire. Forming up for an attack further south from where Company 'I' had attacked the day before, one platoon was sent on a reconnaissance along a steep, narrow ridge. Receiving heavy fire, it was forced to fall back and artillery was called in. This had only limited results due to tree bursts; nevertheless, half an hour later, a second platoon was thrown in and this too was turned back by stiff resistance.
Once again indirect fire support was called in, this time lasting only ten minutes but augmented by mortar fires, after which a flanking attack was attempted. This proved unsuccessful and as night fell, Company 'K' withdrew. The next day, however, Marine patrols found that the Japanese had abandoned the position during the night. Four Marines had been killed and eight wounded in taking the position; only one Japanese body was found when the position was searched later.
Battle of Hellzapoppin Ridge and Hill 600A