National Geographic : 1900 Jan
THE COPPER RIVER DELTA ing the month of September and last through the winter until early spring. They are of such violence that it is impossible for any one to cross the delta while they prevail. The body of water intervening between the flats and the ocean reefs is navigable to boats drawing from three to four feet of water, and is in places navigable to these only at high tide. By the receding tide an area of about 250 square miles is completely drained, and the sur face presents one unbroken expanse of mud. The currents during the rising tide are extremely swift, as the ocean reef acts as a barrier until the water rises over it, when it flows in with great rapidity. The average temperature of the delta during the months of June, July, and August was found to be about 500 F. During the month of Sep tember it is 100 less, accompanied by freezing weather during the nights. The vegetation is very marked. On the flats are found flowers and marsh grass; on the sand dunes are alders, berry bushes, and cottonwood trees, while on the mountain side hemlock and firs grow in abundance. From the head of the delta to where the river leaves the marsh and spreads out over the mud flats it flows nearly south, is about five miles wide, and consists of numerous changeable channels, varying in depth from five to twenty feet. The river breaks through the mountain range about 30 miles from the coast, and is here flanked on the east side by Miles Glacier and on the west by Childs Glacier. In this vicinity are the rapids, which form an insurmountable barrier to all kinds of upstream navigation except canoes. The most westerly branch of the delta is known as the Alaganik Slough, being the most extensively traveled and important branch of the river. Its length is about 15 miles, and it varies in width from one half mile to one mile, with depths from five to fifteen feet, de pending on the stage of the tide. This branch is a tidal stream. The average tide at the lower end during the stay of Mr Ritter's party was about ten feet, while at Alaganik, at the upper end, the tide was from two to three feet. The navigation of this branch is facilitated by the fact that during flood-tide the direction of the current is east, while at ebb-tide it is west. This effect is felt as far as Alaganik. On the Copper River delta are two large canneries, one at Orca and the other at Odiak. The fishing season begins about May and ends with July. During this time each cannery turns out about 30,000 cases. E. D. PRESTON.