288 A Becent Visit to Lake Itasca — Uphain. 



north from the mouth of Itasca, is 1,373 feet above the sea. Be- 

 tween the lake and this point the river probably falls about seventy- 

 five feet, from which estimate the elevation of lake Itasca is 

 shown to be 1,450 feet approximately. On the east, south, and 

 west the land rises within a distance of one to three miles from 

 the lake to heights 100 to 250 feet above it, as determined baro- 

 metrically by Mr. Clarke, or 1,550 to 1,700 feet above the sea; 

 and the highest lakes that probably drain underground to lake 

 Itasca, in Sections 3 and 4, Town 142, Range 36, three to four 

 miles south of its Southwest arm, have a height of 101 feet above 

 Itasca, as determined by levelling under Mr. Brower's direction. 

 The highest hills enclosing the Itascan basin on the south and 

 west have thus nearly the same altitude above the sea as the tops 

 of the Leaf hills in southern Otter Tail county; but they lack 

 about 300 feet from reaching the height of the Coteau des Prairies 

 in southwestern Minnesota, and 500 or 600 feet from the highest 

 parts of the Mesabi range and other hills in the northeast part of 

 this state between lake Superior and the international boundary. 

 A line drawn from Minneapolis to Winnipeg ascends gradually in 

 the southern half of its extent from 830 feet above the sea here 

 to about 1,600 feet at the height of land three miles south of lake 

 Itasca, the average ascent being very nearly four feet per mile; 

 and thence an equal rate of gradual descent falls to 757 feet above 

 the sea at Winnipeg and 710 feet at the level of lake Winnipeg. 



All the country about lake Itasca consists of the glacial and 

 modified drift, the nearest outcrops of the bed-rocks being east- 

 ward on the Little Boy river and southward near Motley. The 

 thickness of the drift there may be estimated between 100 and 200 

 feet, from comparison with the similarly drift-covered areas of the 

 Red River valley and all western and southwestern Minnesota, in- 

 cluding the Coteau des Prairies, where the depth to the bed-rocks 

 is ascertained by wells. Over the preglacial surface, as it had been 

 sculptured into hills, ridges, and valleys by stream-erosion before 

 the Ice age, the drift is found to be spread with a somewhat uni- 

 form thickness, but it is generally increased 50 to 75 or 100 feet 

 in its depth upon belts of specially hilly and knolly deposits, with 

 abundant boulders, which are called terminal moraines. 



One of the most distinct morainic belts of this state, denomi- 

 nated the Itasca moraine, extends with a width of five to ten miles 

 from the south side of Pokegama and Leech lakes westward to 



