PART f 
DISTRIBUTIVE RELATIONSHIPS OF THE 
AGRICULTURAL PATTERN 
ORIENTATION 
L he location and extent of the American Bottoms.—Between Alton and 
Prairie du Pont Creek a notable expansion of the flood plain of the 
Mississippi River is known as the American Bottoms? (Fig. 1). The 
adjoining bluffs of weak Pennsylvanian rocks, overlain with glacial and 
loessial deposits, attain a maximum height in excess of two hundred feet 
above the flood plain but have been weathered and mellowed to such 
an extent that in most places it is possible to walk without difficulty to 
their summits (Fig. 2). Moreover, the continuity of the bluffs is inter- 
rupted here and there by valleys with intermittent or perennial streams. 
The northern terminus of the American Bottoms is marked by a bold 
©scarpment of limestone between which and the river a semi-artificial 
strip of lowland is barely wide enough for one railroad and one highway 
(Fig. 3). The southern terminus of the American Bottoms is similarly 
marked by precipitous limestone bluffs (Fig. 4). Between these bluffs 
and the river the flood plain is less than four miles in width. 
The area of the American Bottoms is slightly in excess of one hundred 
thousand acres, of which about two-thirds is located in Madison County 
and about one-third in St. Clair County, Illinois. The region has a 
maximum north-south extent of about twenty-four miles and a 
Maximum east-west extent of about eleven miles. 
Salient features of the American Bottoms—The American Bottoms is 
@ nearly level alluvial plain approximately one-sixth of which consists 
‘tion (213 manuscript pages) which incluaes 
Part I is essentially the same-as € 
1T 2 arti.) ene | of) 254k pw. A 
17 maps, 32 graphs, 7-tables, and 44 pictures. 
ter I in the complete dissertation. 
: 20)" M. Fenneman, Physiography of the St. Louis Area (Urbana: University of Illinois, 
+m 3, 
