from the Owen Stanley Mountains lose themselves in swamps of nipa, mangrove, and sago trees, which often extend to the coast. The Girua River is typical. It is 40 to 60 feet wide until it disappears in the swamps southeast of Buna Village, and it eventually reaches the ocean through several mouths between Buna and Sanananda. One of these mouths is Entrance Creek, which opens into a shallow lagoon between Buna Village and Buna Mission. Simemi Creek, another stream important in the fighting, runs north to the vicinity of the Buna airfield and then parallels the northern edge of the field to the sea.
The principal swamp in the Buna area lies between Entrance Creek and Simemi Creek and reaches inland to the vicinity of Simemi and Ango. It is absolutely impenetrable, a fact of vital importance in the campaign. Between the closely spaced trees, which are 25 to 100 feet high, is a tangle of roots, creepers, and underbrush. A man standing up can see from 5 to 30 yards; from a fox hole visibility is practically zero. Much of the other ground in the area, though not actually swamp, is thoroughly waterlogged, but a few places near the shore are fairly dry.
Most of the drier land is covered with a thick growth of kunai grass or plantations of coconut palms. This coarse grass grows to a height of more than 6 feet, but its height varies greatly, depending on how recently it has been burned over or cut. Its leaves are broad and sharp-edged; its stems are about the thickness of a pencil. The coconut palms are usually planted about 18 feet apart and the ground under them is relatively clear of cover. Between the mouth of Simemi Creek and Buna Mission lies a government coconut plantation about 300 yards wide; running south from Cape Endaiadere is the Duropa Plantation, about 700 yards wide and 1,800 yards long. To the southwest of this latter plantation is a large area overgrown with kunai grass. Another even larger area of grass occupies the region to the north of the main swamp.
In this open ground southeast of the Mission lies the most important objective of the Allied drive, the landing field. This landing field is 105 air miles from Port Moresby, 147 from Salamaua, and 400 from Rabaul. In Allied hands it would definitely check any enemy threat by land to Port Moresby and, as proved later, would be a powerful support for further advance along the north coast of New Guinea. The landing field was in existence before the Japanese came, but during the
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