20 GUIDEBOOK OF THE WESTERN UXITET> STATES 



whicli differs from the others in that it contains chalk similar to that 

 of the well-known chalk cliffs of England. Some of the deep wells 

 of this region encounter salt water in the shale and chalk rock. This 

 is excluded from the wells by the casing, so that it does not mingle 

 with the fresh water from the underlying Dakota sandstone. Other 

 evidence of the former presence here of sea water are fossil shells of 

 oysters and other animals that live in salt water and the hones of 

 sea monsters such as Mosasaurus. (See PL V^ B, and map on stub 

 of sheet 2, p, 22.) 



A comparison of these ancient conditions with those of the present 

 day indicates the slow, continuous change that is now and always 

 has been in progress. ^Yhere the tourist now travels comfortably 

 over a dry plain, these monsters sported in the water of the sea long 

 ages ago. On the shores of this ancient sea lived equally strange 

 beasts and birds of types that have long been extinct, and over its 

 water sailed great flying dragons — the pterodactyls. The animals 

 of that day were strikingly different from those of the present. The 

 birds, unlike any now living, had jaws armed with teeth. The 

 monarchs of the air then were not birds but flying reptiles, whose 

 fore limbs had been modified into wings by the enormous elongation 

 of fingers between which stretched thin membranes like the wings 

 of a bat. (See PL V, C.) These flying dragons, some of which had 

 a stretch of wing of 18 feet, were carnivorous; they were animated 

 engines of destruction that somewhat forcibly suggest the modem 

 war airplanes, of which they were in a sense the prototypes, 



Columbus, the seat of Platte County, stands in the center of a 

 fertile agricultural district. In 1864 it was a frontier town consistmg 



of a few scattered shacks; but, with total disregard for 

 Columbus. things as thev are and with true western confidence 



Elevation 1,444 feet, in things as they should be, George Francis Train, one 



omaim oi^ndies. ^^ it^ citizcus, then announced that Columbus was the 



geographic center of the United States and therefore 

 the proper place for the national capital. Half a century has 

 elapsed, however, and the seat of government is still at Washington. 

 Columbus is on Loup River, or Loup Fork, as it is usually called, 

 near its junction with the Platte. The Loup is a' stream of consid- 

 erable volume and nearly constant flow, draining 13,540 square miles 

 of the sand-hill region of northwestern Nebraska. West of the mouth 

 of the Loup the Platte usually consists of small irregular streams 

 among the sand bars, forming a lacework of small channels, whose 

 pattern changes with every flood. Although the Platte is normally 

 a large river, draining 56,900 square miles and having a maximum 

 discharge near Columbus of 51,000 cubic feet a second, there is little 

 or no water in it above the Loup during the dry season, the water 

 being diverted for irrigation farther upstream. 



