The Cordova daily times., 1914-12-24
YUKON |S IF HI LARGEST RIVER
 IN AMERICA

The Yukon river in Alaska is onC of the great rivers of the Nortl American continent. A brief report on the discharge of Yukon river al Eagle. Alaska, by E. A. Porter ana R. w. Davenport, has just been is sued by the United States Geologico Survey as Water-Supply Paper 345-F Probably few people have an adequate conception of the size of this river and characteristics of it's flow. A. H Brooks, of the Geological Survey | gives the Yukon fifth place among the large rivers in North America and es inmates it's drainage area at about : 33O,000 square miles. Its length, in. cluding the Lewis and Teslin rivers. Is given in the report at 3.200 miles This may be compared with 5000 miles for the Mississippi and Missouri, ?, S6S miles for the Mackenzie, 2,OOO for the Colorado combined with Green river. and 1900 for the Ohio combined with the Allegheny.
 The discharge of the Yukon varies from a maximum of 2540O0 to a minimum of 10,100 cubic feet a sec ond. or an estimated average flow of 73,2OO cubic feet This is a relatively small discharge. the average flow of the Mississippi being 695,OOO. that of the Ohio 3OO,OOO, and that of the Col. orado 23.3OO second.feet. The Nile with drainage of 1,262,OOO square miles, has an average of 116,OOO cubic feet second The flow of the ypko, is therefore relatively small as related to It's drainage area, and this apnarapt anomaly is accounted for by the fact 'hat the interior of Alaska has the small rainfall characteristic of tbo+ portion of the United States which lies between the Sirra Nevada and tbo Rocky Mountains, north of the Iati. tude of Salt Lake City"
 Navigation on the Yukon has so important a bearing on transportation in interior Alaska that 1t has given rise 10 general recognition of two seasons the closed season" wbor the Yukon Is either filled with float. Ing Ice or frozen over. and the "open season The breakup of the ice usually occurs about the middle of May, after which the river is open to transportation for five or six months or little longer, The breakup is mt only an event of great economic sippi. iicance to the inhabitants in the intari. or or Alaska, but it presents features Of great dramatic interest AS wall One who has not witnessed 1t, according to the authors of the Survey report, can hardly imagine the impressiyeness Of the spectacle, Tram bank to hank the surface of the river is a solid mass Of huge moving ice cakes, which are constantly grinding and distinte- grating with an awe inspiring exhibl. ton of resistless force.
 The freezeup is less spectacular With the increasing cold os the aut. umn s!ush ice forms in the river. and as the cold becomes more intense the ice increases in volume until finally fl is sufficient to bridge the entire stream. This means the termination Of navigation on the Yukon until the following May.
 The Geological Surveys measure. ments of stream flow near Eagle were made during the winter at a point 2 miles above the town, where the river is 1,6OO feet wide, by cutting holes through the ice at intervals of 50 feet and making soundings. In this way the exposed section of the river was determined, and the velocity of the stream at each hole was determined by Price current meter During the period of breakup discharge meas urements were made by means of ice noats. In the open season the flow was determined by the same method as on any large river.
 The maximum discharge measured in 1911 was on May 22, when the vol ume was 253,000 second.feet. The width of the water surface at the measuring section was 1.645 feet, and the greatest depth of the river was 2S.7 feet. The average surface yelo. Il t.ttx