xxxvi 



INTRODUCTION. 



higher grounds are covered with gravel and erratic masses, supporting a scanty 

 vegetation, while the valleys are either wet and marshy, or filled with numerous 

 pools, ponds, and lakes, the borders of which are inhabited by flocks of sand-hill 

 cranes, which fill the air with their doleful cries, and where the eye may often 

 wander in every direction towards the horizon, without discovering even a faint 

 outline of distant timber. 



This description of country prevails for about three-quarters of a degree of lati- 

 tude, and between three and four degrees of longitude, embracing the water-shed 

 where the northern branches of the Red Cedar, and Iowa, and the eastern branches 

 of the Des Moines, take their rise. After passing the extreme sources of the Man- 

 kato, the country again improves, both in the quality of the soil and in the distri- 

 bution of timber. On fairly entering the valley of the Minnesota River, we again 

 find a fertile, well-watered, and desirable farming country. The second terrace of 

 land bordering the Minnesota may be especially cited for its fertility and advanta- 

 geous position, elevated entirely above the highest freshets, and in proximity to 

 a belt of forest, which crosses the Minnesota about latitude 44° 30', and which 

 is remarkable for its unusual body of timber, in a country otherwise but scantily 

 supplied with wood. 



Mr. Macy and Dr. Shumard report a large body of fine arable land adjacent to 

 the St. Peter's and Mankato Rivers. A tract of the best quality of second-rate land 

 extends for three hundred miles on these streams, with an average width of more 

 than a mile, and elevated far above high-water mark. Its siliceo-calcareous soil 

 contains sufficient argillaceous earth to make it retentive of moisture, and varies 

 from one to three feet in depth, resting either on drift deposits or immediately on 

 the rocks of the country. 



The only body of timber throughout this region is the forest above-mentioned, 

 known as the Bois Franc, about twenty miles across, extending from the St. Peter's, 

 south to the heads of the streams flowing into the Mississippi. The rest of the 

 country is open prairie, the streams only being skirted with wood. 



The alluvial lands subject to occasional overflow vary in width from a quarter of 

 a mile to a mile or more. These form either natural meadows, covered with a 

 luxuriant growth of grass, or are timbered with ash, elm, sugar, and white maple. 



The drift-soils west of the Mississippi, except near the northern boundary of Iowa, 

 are much superior to the drift-soils of the interior of the Chippewa Land District, in 

 Wisconsin, the materials that compose them being not only more comminuted, but 

 more generally intermixed with argillaceous, saline, and calcareous ingredients, and 

 less encumbered by erratic blocks. 



The result of a series of barometrical observations, made by Mr. B. C. Macy, 

 gives seven hundred and fifty feet for the fall of the whole length of the Chippewa 

 River, from its source to its mouth, and consequently, the elevation above Lake 



