SOURCE OF ST. PETER's RIVER. 223 



both in the valley and upon the adjacent highlands, so that 

 forests of any considerable extent are entirely excluded. 



On the upper part of the river the valley assumes a dif- 

 ferent character, expanding in some cases to the width of 

 two or three miles, and embracing extensive tracts of roll- 

 ing or level prairies. The bottoms are more elevated, and 

 seldom give place to swamps or ponds. The woodlands 

 become less frequent, and the prairies more extensive, till 

 at length all that appears of the former are mere skirts 

 fringing the water-courses. 



The uplands on both sides of the valley are of a rolling 

 aspect, in some instances inclining to hilly; rocks occasion 

 ally appear upon the surface, but are no where abundant. 

 The stratifications, on which the country is based, consisl 

 of secondary sand and limestone, perforated in several 

 places, towards the head of the river, by peaks and ridges 

 of primitive rock, which rise twenty or thirty feet above 

 the water-table of the country. The aggregate descent 

 of the St, Peter may be estimated at about one hundred 

 and fifty feet,* the general level of the country at its source 

 having an elevation of about eighty feet above the river. 



On retiring from the river in either direction the coun- 

 try becomes undulatory, but no hills remarkable for their 

 magnitude occur, till we arrive at the Coteau des Prairies, 

 on the west, and at the Pine ridges, &c. which are repre- 

 sented as the birth place of the waters of the Mississippi, 

 on the east. The height to which these last attain is said 

 to be inconsiderable ; they do not probably rise more than 

 a few feet above the general level above mentioned. 



• In vol. 1. p. 364, the descent of the St. Peter was from general 

 considerations estimated at sixty feet, but ]Major Long is of opinion 

 that one hundred and fifty feet accords better with known facts in re- 

 lation to the descent of water-courses. 



