THE GREAT PLAINS OF THE UNITED STATES 273 



huts or hogans, are but scattered remnants of what were 

 formerly widespread. 



On old plateaus travel is easy. There are no deep valleys, 

 and one can easily pass around the mesas, which only add 

 charm to what would otherwise be a most monotonous 



CLIFF DWELLINGS, ARIZONA 

 A protected retreat in a mesa. 



landscape. When these mesas are high, they are some- 

 times occupied by a few Indian tribes who have fled to 

 them for protection, as the medieval barons when hard 

 pressed fled to their isolated castles. 



The Great Plains of the United States. No exact dis- 

 tinctions may be made between plains and plateaus. Some 

 surfaces partake of the nature of both. West of the Mis- 



