36. Wisconsin and Missouri Lead Region. 
horizontal, until by tracing them some miles, a prevailing dip to 
the south is discovered. 
The lead region is a rolling hilly country, the hills sometimes 
covered with an open growth of oak, but as often entirely free of 
timber, and clothed with the tall prairie grass only. The sum- 
mits maintain a general level, except where it is broken by the 
‘natural mounds,” (the two Blue mounds, the Platte mounds, 
Sinsinava mounds, &c.) which rise several hundred feet above 
it. In these the limestone appears more siliceous than is noticed 
elsewhere, and its superior hardness may in part have been the 
cause of these mounds remaining like monuments of the devas- - 
tating currents that must have given the surface around its pres- 
ent form; while the huge blocks, tipped out of their horizontal 
position, lie on the steep sides as additional evidence of the wast- 
ing waters. Yet these are the only evidences that such a force 
has been in operation ; for in the western part of Wisconsin, there 
are no primary bowlders, no loose rocks but those which once 
evidently formed a part of the formations on which they now 
repose ; in the eastern part of the territory, however, and to the 
west in Iowa, such bowlders are not wanting. Whether this 
region may have been in part protected by the high lands to the 
north of it, and the progress of the bowlders been thus intercept- 
ed and turned aside, must be determined by more extended ob- 
servations. This supposition is rendered more plausible by the 
unusual course of the Wisconsin river, it suddenly turning from 
a south toa west direction. In its valley, however, where it 
flows towards the west, no bowlders are found except the small 
pebbles brought down by the river itself. 
Throughout the extensive tract defined as the lead region, lead 
ore may be sought for with prospect of’ success on every town- 
ship and on almost every square mile. And fortunately it is so 
well watered, and the little streams have so rapid a fall, that 
power for furnaces may almost always be obtained near the mines: 
New discoveries are continually made, and with every one fur- 
ther light is thown upon the true character of the ranges of fis- 
sures containing the lead and copper ores ; by which result they 
eau be traced with greater certainty from one tract to another, 
—- uae entirely on the present imperfect system of 
mee ttc ah Sheetal age 
