108 The American Geologist. August, 1903. 
The portage and the course of the Fox river for several 
miles below it display indubitable features as the channel of a 
much larger stream formerly outflowing from the Fox basin. 
It is a distance of only one and a half miles from the small 
head stream of the Fox river, there only two or three rods 
wide and a foot deep at low water, to the majestic Wisconsin 
river, there carrying the drainage of about 8,000 square miles, 
equal to the state of Massachusetts. 
An ascent of about ten feet is made on the ■ old portage, 
passing over very flat alluvial ground from the Fox to the 
Wisconsin, and the descent from its upper southwestern end 
to the level of the large river at its ordinary stage is only five 
feet. During flood stages in the spring, or after heavy rains 
at anv season, the Wisconsin here overflows its watershed, 
which indeed almost immediately adjoins its bank, and sends 
a part of its water down the Fox river. It also similarly over- 
flows, at its times of flood, six to seven miles northwest of 
Portage, into Neenah creek, which runs north and east to 
join the Fox river after a course of about twelve miles. 
Between the former sites of Fort Winnebago, close east of 
the Fox river, and the Indian Agency, close west of this river, 
at the distance of about two miles from the Wisconsin, a chan- 
nel was eroded in the drift by the outflow from the glacial 
lake of the Fox valley to a depth of 35 to 40 feet, with a width 
of about 1,000 feet, along the distance of a quarter of a mile. 
The original surface there was about 30 feet above the Wis- 
consin river at Portage, and this channel could not have been 
due to erosion by the present Fox river, which runs through it, 
nor by any discharge from floods of the Wisconsin, which in 
this part has a range of about 10 feet from its lowest to its 
highest stage. 
Thence the Fox river has a descent of only a few feet along 
its course for twenty-five miles northward. In the northern 
two-thirds of this distance it expands to form Menomin and 
Buffalo lakes, six to nine feet deep and about a half mile wide, 
having together a length of fifteen miles. They are thus very 
shallow, and are mostly filled in summer with an abundant 
■growth of wild rice. This part of the upper Fox river evi- 
dently occupies the ancient eroded channel of a larger river 
which flowed in the opposite direction, being tributary to the 
Wisconsin valley. 
