GEOLOGY OF SOUTHWESTEEN IOWA. 371 



such a character that they would be valuable in any region. 

 All of the stone is suitable for ordinary purposes, and for the 

 production of lime, and many of the layers also furnish 

 blocks suitable for bridge building, and for dressing into 

 caps and sills for buildings. The localities in this vicinity 

 may be made to furnish an abundance of the material 

 mentioned. 



Mr. Peter Cooper has quarried and dressed considerable 

 quantities of the Nishnabotany sandstone at the exposures 

 before mentioned, in the northeastern part of the county. 

 This stone serves a very good purpose for some parts of 

 buildings, if selected with care, but it is too soft, even after 

 it has received its usual hardening by exposure, for those 

 structures which require great strength of material. 



Although the vertical range of the Upper coal-measure 

 strata of Mills county includes the horizon of the Nodaway 

 valley coal-bed, yet the coal itself has not yet been found 

 within its limits. Consequently, if coal is ever obtained, it 

 must be sought by deep mining beneath the level of its 

 deepest valleys. As to the probabilities of finding it by 

 such mining, the reader is referred to the closing section of 

 the chapter on the Upper coal-measures in another part of 

 this report. 



The county is well supplied with fuel from its woodlands, 

 and the young growth of indigenous forest trees before men- 

 tioned, is increasing so rapidly that there is no cause to fear 

 that the supply from this source will become exhausted. 



15. CASS COUNTY. 



Boundaries and Area. Cass, is the second county east- 

 ward from the Missouri river in the third tier from the 

 southern boundary of the State, lying east of Pottawattamie 

 and west of Adair counties. It is exactly square in outline, 

 being twenty -four miles from east to west and the same from 

 north to south. Consequently, it contains five hundred and 

 seventy-six square miles, or three hundred and sixty-eight 

 thousand six hundred and forty acres. 



