Flying up a valley close to treetops was extremely dangerous because it was very difficult to judge the incline, [which was] often greater than the aircraft's maximum rate of climb, so that even with full throttle the plane could not climb out of the valley. Furthermore if the valley sides were … narrowing sharply, it was very easy to misjudge the point where there was enough turning space left. … There were many times when I thought I had misjudged it and came out with heart pounding.
Alex Miller-Randle quoted in Mark Johnston, The Markham and Ramu Valleys, p.9. Read more about his and the experiences of others.
Location
The Ramu River stretches from the Kratke Range northwest to the Bismarck Sea. The rugged Finisterre Ranges lay between the Ramu Valley and Madang.
Strategic situation
In 1942, Japanese forces seized the Territory of New Guinea from Australia. Australian and US forces fought several costly battles to recapture the territory, often fighting in difficult terrain while battling widespread tropical illness.
The Australians defeated the Japanese at Wau early in 1943 and captured Salamaua on September 11. Lae was captured on September 16, after which, the 7th Division was ordered into the Markham-Ramu Valleys. The Allies fought the Battle of Dumpu in September to October 1943. The Australian 7th Division then fought the Japanese across the Finisterre Range, on Shaggy Ridge, which fell in late January 1944.
The outcome
Capture of the valley allowed the Allies to build a forward airbase at Gusap.
Learn more about Shaggy Ridge