Lakes Near Laporte 83 



HISTORY OF THE LAKES NEAR LAPORTE, 

 INDIANA. 



W. M. Tucker, Indiana University. 



In October, 1921, the writer's attention was called to the recession 

 of the lake level in the vicinity of LaPorte, Indiana, by an appeal from 

 the Park Board of LaPorte to the State Conservation Commission for 

 suggestions as to the cause of the recession and means of raising the 

 lake level. Since that time I have spent about three weeks in the field 

 about LaPorte and have found a peculiar and very interesting problem. 

 On my first visit to LaPorte I was accompanied by Prof. Will Scott 

 of the Zoology Department of Indiana University and on my third and 

 last visit I was assisted by Mr. W. A. Thomas, a student of Geology 

 at Indiana University. I wish to acknowledge the services and sugges- 

 tions of these men and also Mr. Maurice Fox, President of the Park 

 Board of LaPorte; Dr. W. N. Logan, State Geologist; Mr. Burtis Thomas, 

 City Engineer of LaPorte; Mr. Robert Day, Assistant City Engineer; 

 Mr. W. A. Cummings, Park Superintendent of LaPorte; Messrs. 

 J. W. and Archie Good, well drillers of LaPorte and many others whose 

 suggestions and services were of value. 



PHYSIOGRAPHY AND GEOLOGY OF LAPORTE COUNTY. 



The physiographic conditions of LaPorte County are dominated by 

 the influence of the Wisconsin glaciation. Mantle rock derived from 

 glaciation overlie the Devonian limestones and shales to a depth of 100 

 to 250 feet or more. There are no bed rock exposures in LaPorte 

 County. By reference to figure 1, the type of surface rock are evident. 

 The southeastern 60.1 per cent of the county is an old lake flat. It is 

 now called the Kankakee valley or Kankakee lowland. This legion 

 slopes gently toward the south from an elevation of somewhat less than 

 800 feet on the north to the Kankakee River somewhat above 700 feet 

 on the south. The average slope of this region is about five feet per 

 mile. Gravels and sands on the north merge into finer sands, clays and 

 peat on the south. Great areas along the Kankakee were covered by 

 swamp until recent drainage projects have reduced them materially. 

 Considerable swamp land still prevails, however. 



Lying northwest of this lake flat is the great Valparaiso moraine. 

 This area comprises 29.6 per cent of the county. The crest of this 

 moraine is represented in general by the divide on figure 1 and that 

 part lying north and west of LaPorte is shown accurately. This crest 

 is undulating reaching elevations about 950 feet and seldom reaching 

 lower elevations than 900 feet. The south margin of the moraine has 

 an elevation of about 800 feet, usually slightly less. The north margin 

 has an elevation of from 650 to 680 feet. Thus the north slope is much 

 steeper than the south slope. The surface of this moraine is of the 

 knob and basin character typical of well developed morainic regions. The 

 north slope is undergoing severe stream erosion where the tributaries 



"Proc. 38th Meetins-, 1922 (1923)." 



