FLY RIVER, a large stream in southern New Guinea, the largest in Papua (British New Guinea). It rises in the Victor Emanuel mountains near the centre of the island and flows first south and then southeast into the Gulf of Papua. It is about Boo m. in length and is navigable with a steam launch for a distance of 535 m. from its mouth. For approximately 1 oo m. it forms the boundary between British and Dutch New Guinea. The Fly river enters the Gulf of Papua in a great estuary nearly 5o m. across which is filled with a series of low shifting mud islands. The larg est, Kiwai, lies in the centre of the estuary and is inhabited. The effect of the tide is felt for a distance of I5o m. up the river, and at the point where it ceases the stream is 600 yd. wide and averages 39 ft. in depth. About 30o m. from its mouth the Strickland river, a tributary as large, and perhaps larger, than the Fly, enters from the north, having its source also in the Victor Emanuel moun tains. About Soo m. from the mouth another large tributary, the Alice comes in from the right. Perhaps 55o m. from the mouth the Fly river divides into two nearly equal branches, the one from the left, named the Palmer, being regarded as the tributary. There are no white settlements in the whole vast extent of terri tory drained by the Fly river, and for the last 40o m. of its course the land is too low and unhealthy for white occupation, though the natives are fairly numerous. The low country is inundated an nually. The first hills are found about 48o m. up the river, and from here on nights are cool and the climate healthier. Despite its great navigable length the river is commercially unimportant.
The mouth of the Fly river was discovered by Capt. Blackwood in 1842 and named after one of his ships. It was first explored by Macfarlane and D'Albertis in 1875-76, and in 1877 by D'Al bertis alone, who ascended to the entrance of the Alice river. In 1885 Capt. Everill discovered and ascended the Strickland river which D'Albertis had missed. The Alice was not explored until in 1913 by Murray and in 1922 by Austen. In 1927 Champion first made his way to the headwaters of the Palmer river, and Karius crossed to and descended the Strickland river.
See L. M. D'Albertis, New Guinea (188o) ; J. H. P. Murray, Papua (1912) ; W. N. Beaver, Unexplored New Guinea (192o) and The Annual Reports of the Governor-general of Papua.