6 FIELD OPERATIONS OF THE BUREATt OF SOILS, l»li). 



that tho soils over tlio ^ivuter i)art of this phiin show ovidonco of poor 

 draina^a' either at the ])resent time or until within a very recent stao:e 

 of their (leveh)i)nient. No hikes occur in this phiin except Wall 

 T^ake, near its eastern border. 



The morainic part of the county possesses a greater variety of topo- 

 graphic featui'es. The region consists of a gently to sharjjly rolling 

 j)lain traversed by chains of morainic hills. Some parts of this mo- 

 rainic section are almost as smooth as the till plain, but the general 

 average, even at some distance from the moraines, is more rolling. 

 The morainic hills range in prominence from mere swells to sharply 

 rounded hills which stand up above the general level of the country. 

 A very prominent chain of hills occurs a few miles northeast of 

 Clarion, along the eastern side of Elm and Cornelia Lakes. Branch- 

 ing fi-om this chain of hills a small range extends southward about 



7 miles, passing 2 miles east of Clarion. Another chain leaves the 

 main range west of Dows, extends in a northeasterly direction, and 

 crosses the county line about 3 miles north 9f Dows. This range is 

 cut through by the Iowa Eiver. In the vicinity of Dows a few iso- 

 lated hills or mounds, which are so regular in shape as to appear arti- 

 ficial, rise above the general level of the plain to a height of 40 or 

 50 feet. The land surface in the morainic area is almost unchanged 

 by the effects of erosion. Many marshes and sloughs wind among the 

 hills, but no drainage channels have begun rapid erosion. Nearly 

 one-third of the total area of the morainic region is either flat or 

 lacking in drainage outlets, so that it shows effects of poor drainage. 



A chain of shallow lakes, ranging in size from 320 to 1,200 acres, 

 lies along a north-and-south line a little east of the .center of the 

 county. Morse, Cornelia, and Elm Lakes lie in the morainic hills, 

 while Wall Lake, the largest, lies in the level prairie. 



First bottoms, or alluvial flood plains, are developed along all 

 the main streams and for distances of from 1 to 5 miles along their 

 tributaries. They range from 50 feet to about three-eighths of a 

 mile in width. Second bottoms, or terraces, are found only along 

 the Iowa River, the West Branch of the Iowa, and the Boone River, 

 and along a small creek which enters the Iowa River about 3| 

 miles south of Dows. On this creek and at Belmond, on the Iowa 

 River, two terraces are developed, one about 8 feet above the level 

 of the first bottom and the other about 15 feet higher. 



The highest elevation in the county occurs on the morainic divide 

 just east of the center of the county. Three miles east of Clarion 

 the altitude is given as 1,240 feet above sea level. The lowest 

 elevation, 1,108 feet, is in the west-central part of the county at 

 Goldfield. This gives a variation of 132 feet between extremes. 



