362 GRASSES OF IOWA. 



the Rocky Mountains, more than a thousand miles away. From the 

 highlands of the Lake Superior region to the low shore of the Gulf of 

 Mexico it is broken only by the dome of the Ozarks and the adjacent 

 ridges of the Ouachita mountains, the cut off and practically buried west- 

 ern extension of the Appalachians. In the northwest the valley is diver- 

 sified by outlying spurs of the Rocky Mountains, and its floor has been 

 perforated by the isolated group of peaks known as the Black Hills. 

 Around the edges of this great area which the Mississippi has made its 

 own, rise some of the important mountains of America. Out into it they 

 sometimes project, though never far. The territory is not for the moun- 

 tains and they are either worn away by the rivers or buried beneath the 

 level expanse of softer rocks. In the main the region is one of slight re- 

 lief. It is open, largely treeless, and shows but little diversity except in 

 minute features. These facts are especially true of the western half to 

 which Iowa belongs. This portion is a vast, open plain cut only by the 

 rivers, and rising with an even, gentle slope from about 500 feet above 

 tide at the Mississippi to 5000 feet along the foot of the Rockies. It is a 

 region of grass land, dotted with clumps of trees along the low banks of 

 gently winding rivers; a region of deep, rich soil; a region where bar- 

 riers, other than those of climate, are rare, and plants as well as animals 

 have open to them a wide range. In these later days it is a region of 

 fruitful farms, heavy with the staple grains, and of wide pastures of suc- 

 culent herbage. The abundant grass, the cheap corn, the frequent 

 streams of good water and the nearness to markets make it inevitably 

 a great dairy and cattle country, and the prosperous little cities and thriv- 

 ing villages found throughout the state are but the promise of the denser 

 population of the years to come. 



Examined in detail Iowa shows, despite the general sameness, a 

 considerable diversity both in relief and resources. The state occupies 

 the area between the Mississippi and the Missouri, the two great rivers 

 of the region, and extends from latitude 40 30' to 43 ° 30'. It is in the 

 heart of the prairie plain region so aptly described by Powell. It has a 

 gentle surface slant to the southeast from about 1500 A. T. in the neigh- 

 borhood of Spirit Lake to 477 at Keokuk. The portion of the state 

 southwest of the divide between the two great rivers slopes more gently 

 to the southwest; the divide itself declining gently to the south. The 

 watershed is not ridge-like, but represents rather a broad, elevated table 

 land running from northwest to southeast. The western border of the 

 state is formed by the Big Sioux and the Missouri, and slopes south from 

 1300 to 900. The Mississippi falls about 165 feet along the eastern 

 border of the state. 



