470 



N. H. DARTON PALEZOIC AXD MESOZOIC OF WYOMING 



!■ 



and Medicine Bow range, but no trace of their presence has been found 

 on the Laramie mountains or Black liills. As Quaternary time pro- 

 gressed, the streams spread wide bodies of alluvial deposits along the 

 wider valleys, and in later times, as the streams cut to lower levels, these 

 deposits remain on liigbcr terraces. 



I 



