The Germans were quick to explore their territory, and the mouth of the Ramu was discovered in 1886 by Vice-Admiral Freiherr von Schleinitz after returning to Finschhafen from an expedition to the nearby Sepik.

[2] After crossing the Ortzen Mountains from Astrolabe Bay south of Madang, Lauterbach's party, instead of finding the Markham, found an unknown river flowing northwest.

[3] After five days of journey up the Ramu, Tappenbeck left his companions at a well-stocked camp when river water levels fell.

He returned four and half months later in another steamer, Herzogin Elisabeth, and the party managed to navigate 190 mi (310 km) upstream and go farther still by canoe.

Moyne discovered a race of pygmy-like people inhabiting the middle Ramu region 170 miles (270 km) from the mouth of the river in the Aiome foothills.