THE GLACIAL LAKE AGASSIZ. 403 



subsequent years I was employed also in tracing the old lake 

 shores through North Dakota for the United States Geological 

 Survey, and in Southern Manitoba, to the distance of 100 

 miles north from the international boundary to Riding 

 Mountain, for the Geological Survey of Canada. For the 

 last named survey, Mr. J. B. Tyrrell extended the exploration 

 of the lake shore lines more or less completely for 200 miles 

 farther north along the Riding and Duck mountains and the 

 Porcupine and Pasquia hills, west of Lakes Manitoba and 

 Winnipegosis, to the Saskatchewan River. 



This glacial lake was named by me in the eighth annual 

 report of the Minnesota Geological Survey, for the year 

 1879, in honor of Louis Agassiz, the first prominent advocate 

 of the theory of the formation of the drift by land ice; and the 

 outflowing river, Tvhose channel is now occupied by Lakes 

 Traverse and Big Stone and Brown's Valley, was named also 

 by me, in a paper read before the American Association for the 

 Advancement of Science at its Minneapolis meeting in 

 1883, the River Warren, in commemoration of General War- 

 ren's admirable work in the United States Engineering Corps, 

 in publishing maps and reports of the Minnesota and Missis- 

 sippi River surveys. 



Descriptions of Lake Agassiz and the River Warren are 

 somewhat fully given in the eighth and eleventh annual reports 

 of the Minnesota Geological Survey, and in the first, second, 

 and fourth volumes of its final report. Three other special re- 

 ports of my explorations of Lake Agassiz were published ; the 

 first in 1887, as Bulletin No. 39, of 84 pages, with a map, by 

 the Geological Survey of the United States; the second in 

 1890, by that of Canada, in its Annual Report, New Series, 

 vol. iv, for 1888-89, forming Part E, 156 pages, with maps and 

 sections; and last, this subject was most fully issued by the 

 U. S. Geological Survey, as its Monograph XXV, 1895, a 

 quarto volume of 658 pages and 38 plates (maps, views, and 

 sections). 



