Despite Japan’s loss of Mount Suribachi on the south end of the island, the Japanese still held strong positions on the north end. The rocky terrain vastly favored defense, even more so than Mount Suribachi, which was much easier to hit with naval artillery fire. Coupled with this, the fortifications constructed by Kuribayashi were more impressive than at the southern end of the island. Remaining under the command of Kuribayashi was the equivalent of eight infantry battalions, a tank regiment, and two artillery and three heavy mortar battalions. There were also about 5,000 gunners and naval infantry. The most arduous task left to the Marines was the overtaking of the Motoyama Plateau with its distinctive Hill 382 and Turkey knob and the area in between referred to as the Amphitheater. This formed the basis of what came to be known as the “meatgrinder”. While this was being achieved on the right flank, the left was clearing out Hill 362 with just as much difficulty. The overall objective at this point was to take control of Airfield No. 2 in the center of the island. However, every “penetration seemed to become a disaster” as “units were raked from the flanks, chewed up, and sometimes wiped out. Tanks were destroyed by interlocking fire or were hoisted into the air on the spouting fireballs of buried mines”. As a result, the fighting bogged down, with American casualties piling up. Even capturing these points was not a solution to the problem since a previously secured position could be attacked from the rear by the use of the tunnels and hidden pillboxes. As such, it was said that “they could take these heights at will, and then regret it”.
The Marines nevertheless found ways to prevail under the circumstances. It was observed that during bombardments, the Japanese would hide their guns and themselves in the caves only to reappear when the troops would advance and lay devastating fire on them. The Japanese had over time learned basic American strategy, which was to lay heavy bombardment before an infantry attack. Consequently, General Erskine ordered the 9th Marine Regiment to attack under the cover of darkness with no preliminary barrage. This came to be a resounding success with many Japanese soldiers killed while still asleep. This was a key moment in the capture of Hill 362. It held such importance that the Japanese organized a counterattack the following night. Although Kuribayashi had forbidden the suicide charges familiar with other battles in the Pacific, the commander of the area decided on a banzai charge with the optimistic goal of recapturing Mount Suribachi. On the evening of 8 March, Captain Samaji Inouye and his 1,000 men charged the American lines, inflicting 347 casualties (90 deaths). The Marines counted 784 dead Japanese soldiers the next day. The same day, elements of the 3rd Marine Division reached the northern coast of the island, splitting Kuribayashi’s defenses in two. There was also a kamikaze air attack (the only one of the battle) on the ships anchored at sea on 21 February, which resulted in the sinking of the escort carrier USS Bismarck Sea, severe damage to USS Saratoga, and slight damage to the escort carrier USS Lunga Point, an LST, and a transport.
Although the island was declared secure at 18:00 on 16 March (25 days after the landings), the 5th Marine Division still faced Kuribayashi’s stronghold in a gorge 640 m (700 yd) long at the northwestern end of the island. On 21 March, the Marines destroyed the command post in the gorge with four tons of explosives and on 24 March, Marines sealed the remaining caves at the northern tip of the island. However, on the night of 25 March, a 300-man Japanese force launched a final counterattack in the vicinity of Airfield No. 2. Army pilots, Seabees, and Marines of the 5th Pioneer Battalion and 28th Marines fought the Japanese force for up to 90 minutes, suffering heavy casualties (53 killed, 120 wounded). Two Marines from the 36th Depot Company, an all-African-American unit, received the Bronze Star. First Lieutenant Harry Martin of the 5th Pioneer Battalion was the last Marine to be awarded the Medal of Honor during the battle. Although still a matter of speculation because of conflicting accounts from surviving Japanese veterans, it has been said that Kuribayashi led this final assault,which unlike the loud banzai charge of previous battles, was characterized as a silent attack. If ever proven true, Kuribayashi would have been the highest ranking Japanese officer to have personally led an attack during World War II. Additionally, this would also be Kuribayashi’s final act, a departure from the normal practice of the commanding Japanese officers committing seppuku behind the lines while the rest perished in the banzai charge, as happened during the battles of Saipan and Okinawa. The island was officially declared secure at 09:00 on 26 March.
Once the island was officially declared secure, the Army’s 147th Infantry Regiment was ostensibly there to act as a garrison force, but they soon found themselves locked in a bitter struggle against thousands of stalwart defenders engaging in a last-ditch guerilla campaign to harass the Americans. Using well-supplied caves and tunnel systems, the Japanese resisted American advances. For three months, the 147th slogged across the island, sing flamethrowers, grenades, and satchel charges to dig out to enemy. Some sources credit the regiment with killing at least 6,000 Japanese soldiers in those anonymous and merciless small unit actions.