358 
BULLETIN OF THE BUREAU OF FISHERIES. 
Table 3. — Elevations of water level of the upper Mississippi River from Lake Itasca, Minn., to Alexandria, 
Mo. 
[Elevations, in feet, above Memphis datum, which is approximately 8.13 feet below mean Gulf level at Biloxi, Miss. The data 
refer to the condition before the construction of Keokuk Dam.] 
Little Elk Lake 
Above St. Anthony Falls. 
Below St. Anthony Falls. 
St. Paul, Minn 
Miles from 
St. Paul, 
Minn. 
Water 
level (feet) 
above 
Memphis 
datum. 
Mean stage 
at the 
days of 
sounding 
(feet). 
Highest 
water 
known 
prior to 
survey 
(feet) above 
datum. 
Hastings, Minn 
Bed Wing, Minn 
Lake Pepin: 
Frontenac, Minn 
Lake City, Minn 
Reads Landing, Minn 
Alma, Wis 
Winona, Minn • 
La Crosse, Wis 
Prairie du Chien, Wis 
Guttenberg, Iowa 
Dubuque, Iowa 
Clinton, Iowa 
Le Claire, Iowa 
Rock Island, 111 
Fairport, Iowa 
New Boston, 111 
Keithsburg, 111 
Oquawka, 111 
Burlington, Iowa 
Dallas, 111 
Fort Madison, Iowa 
Nauvoo, 111 
Lake Keokuk, head of the canal, opposite Galland. 
Keokuk, Iowa, foot of the canal 
Alexandria. Mo 
675.8 
675.1 
674.7 
674.6 
663.3 
650.6 
637.2 
613 
606 
594.4 
574.2 
570.4 
550.2 
542.9 
531.7 
529.7 
525.1 
519.5 
514.1 
510.7 
508.8 
504.7 
695.7 
677.7 
664.1 
’568.’6 
When leaving Itasca Lake the river is only 30 feet wide. In the Wisconsin 
section its width varies from 725 feet at Clayton to 2,400 feet near La Crosse. At 
Rock Island Rapids the narrow part of the river is about 800 feet wide, at Fairport, 
Iowa, it is about 2,600 feet wide, and at Keokuk, below the dam, about 2,000 feet. 
These data, based on the Mississippi River Commission charts, are only roughly 
comparable because they represent different stages of water. Between St. Anthony 
Falls and the mouth of the Ohio, 888 miles below, the Mississippi flows on the narrow 
flood plain between steeps and bluffs forming its gorge and its bed occupies a com- 
paratively narrow part of it, varying from 8 per cent of the width of the flood plain 
at Clayton to 27 per cent at North Dubuque (Martin, 1916). In this portion the 
Mississippi flows through the western edge of the so-called “Driftless Area,” world- 
famous on account of its geological peculiarity. Here the steep bluffs, rising 230 
to 650 feet above the flood plain, form the most picturesque scenery of the Mississippi 
Valley. The river winds from one side of the flood plain to the other, numerous 
islands dividing its channel and forming many sloughs and bays which often are 
transformed by the sand bars into pools of stagnant water. A characteristic feature 
of the Mississippi flood plain is the many shallow lakes or pools, which seldom 
exceed 1 J miles in diameter. When the water is high the river floods the whole 
area, covering these lakes and the spaces between, but in summer many of them 
become almost dry. 
