Finisterre Range campaign The Finisterre Range campaign , also known as the Ramu Valley – Finisterre Range campaign , was a series of actions in the New Guinea campaign of World War II . Several actions in the campaign are sometimes known collectively as the Battle of Shaggy Ridge . The campaign began with an Allied offensive in the Ramu Valley , from 19 September 1943 , and concluded when Allied troops entered Madang on 24 April 1944 . During the campaign , Australian and U . S . forces assaulted Japanese positions in the Finisterre Range of New Guinea . The central geographical and strategic feature of the campaign was the imposing Shaggy Ridge , running north - south in the Finisterres . Forces . The Japanese formation in the campaign was the Nakai Detachment , a brigade - sized formation detached from the Japanese 20th Division under Major General Masutaro Nakai . It faced the Australian 7th Division , consisting of approximately 17 , 000 men under Major General George Vasey , and made up of the 18th , 21st and 25th Brigades , along with the 2 / 6th Commando Squadron . Outline of the campaign . The campaign began in September 1943 following the 7th Division ' s drive on Lae , as part of the wider New Guinea campaign , which saw the 9th Division carrying out operations along the Huon Peninsula on the coast to the east , while the 7th moved towards the west . Carrying out a number of smaller - scale operations , the units of the 21st and 25th Brigades advanced up the Markham and Ramu Valleys . Apart from a significant engagement around Kaiapit , where the 2 / 6th Commando Squadron captured the village and killed over 200 Japanese , the Australians were barely resisted as they advanced and they arrived in Dumpu in early October . Following this , the 7th Division provided security for a number of airfields that were constructed in the territory they had captured in the valleys , however , the Japanese remained in strong possession of the Finisterre Range , and their positions at Kankiryo Saddle north of the Ramu river and the high razorback ridge named Shaggy Ridge , continued to threaten the airfields . This threat manifested itself in the road that the Japanese were attempting to build from Madang on the coast inland to Nadzab , via Bogadjim along which they were hoping to advance through to Dumpu . Thus , the Kankiryo Saddle and Shaggy Ridge were of vital strategic importance for both the Japanese and the Australians . For the Japanese , it provided a strong obstacle to the Australian advance north towards the coast , while also offering them the ground along which they could launch their own offensive in order to recapture the territory they had lost earlier in the campaign . For the Australians , the Japanese positions on the high ground signalled threat and their commander , Vasey , came to the decision that he would have to launch an offensive in order to capture this ground . This led to a number of battles in the steep mountains of the Finnisterres . In October , battles took place at Palliser ' s Hill and then later at Johns ' Knoll where the Australians first managed to capture the knoll and then held it against a determined Japanese counterattack . In November , the 25th Brigade relieved the 21st as the offensive was maintained , and later in December and into January heavy fighting took place around Shaggy Ridge and the Kankiryo Saddle . Shortly after Shaggy Ridge was captured , the 18th Brigade was replaced by the 15th Brigade , a Militia formation , and the 7th Division advanced towards Bogadjim , linking up with the American forces there on the coast , before finally securing the Huon Peninsula on 24 April 1944 when they took Madang . Operation Cutthroat . The major Australian offensives on Shaggy Ridge — codenamed Operation Cutthroat — were launched by the 18th Brigade on 19 January . The plan called for the brigade ' s three battalions to converge on Kankiryo Saddle from three different directions : In Popular Culture . Fighting during the campaign was featured in the Australian documentary " Jungle Patrol " ( 1944 ) .