NOTES ON THE FISH FAUNA OF LAKE PEPIN. 
GEORGE WAGNER. 
[Published by permission of the United States Bureau of Fisheries.] 
Lake Pepin is an expanded portion of the Mississippi River, 
on the southern boundary of the counties of Pierce and Pepin ? 
Wisconsin. The cause of this expansion is the deposition of 
material by the Chippewa River at the point where it joins the 
Mississippi. The Mississippi here was not able to carry this 
extra load. As a consequence, it has been deposited as a sort 
of wing dam, increasing with time and finally forming a con¬ 
siderable barrier against the waters of the Mississippi. These, 
so checked, collected above to form a lake, until a point of 
equilibrium was reached. At present, the height of the lake 
varies through a range, as far as the extremes on record are 
concerned, of about nineteen feet, and through a range of four 
or five feet during an average season. 
Lake Pepin is sigmoid in outline, extending from northwest 
to southeast. Its length along the center line is about twenty- 
five miles; its width varies from one-half mile to two and one- 
half miles. In the main, its shores are steep bluffs; these re¬ 
cede from the Minnesota side for several miles at Lake City, 
and on the Wisconsin bank near the lower end of the lake at 
Pepin. 
At the upper end of the lake, for a mile or more, the bot¬ 
tom is in large part mud. The rest of the lake bottom is 
chiefly sand, with small patches of sand and mud occurring at 
rather regular intervals. The depth at the upper end ranges 
