12 University of Kansas Geological Survey. 
half of the great plains area drains into the Missouri. In the north- 
eastern part of Wyoming, and in Montana, the drainage is to the 
northeast. South from this in Nebraska and Kansas the drainage 
at present is almost straight east, while still further south it be- 
comes deviated more toward the southeast. The waters from this 
part of the plains area enter the Mississippi directly through the 
Canadian and other channels without entering the Missouri. Still 
further south the drainage is into the Gulf of Mexico, either through 
the Rio Grande, or through lesser streams which enter the Gulf at 
different places in Texas. Comparatively few of these different 
streams rise in the mountainous country. The Missouri river with 
its more important tributaries, the Big Horn, the Yellowstone, the 
Powder, on the north, rise in the mountains; as do also the Platte 
river and the Arkansas in the central area; and the Canadian, the 
Pecos, and the Rio Grande farther south. The whole plains area, 
however, is covered with drainage channels, the most of which 
originate east of the foothills of the mountains. The ordinary map 
of the United States will show that the different streams are about 
as abundant over the great plains as elsewhere through the United 
States. 
Of the Kansas streams as they now exist only one rises in the 
Rocky mountains—-the Arkansas. Of the upper branches of the 
Kansas river the Republican rises farthest west. Different branches 
of this stream originate on the plains about one hundred miles west 
of the western boundary of Kansas. The tributaries of the Smoky 
Hill likewise originate across the line in Colorado, but not so far 
away. South of the Arkansas river the Cimarron river exists, 
which takes its rise from near Raton in New Mexico. In fact this 
stream almost might be called a mountainous stream, as its head- 
waters are away up on the highlands of the mountains. Lying be- 
tween the Arkansas and the Cimarron is a little stream called Bear 
creek, which originates fifty miles or more west of the Kansas line. 
At the present time many of these plains streams do not enter 
larger drainage channels. Having their rise in places where the 
inclination is relatively great, they frequently form channels from 
20 to 50 feet deep, and prominent flood-plains, implying that they 
have a considerable age, but farther eastward simply spread out 
