216 Annals of the Carnegie Museum. 



lations, resembling a slight disturbance on a quiet sea ; then all is 

 smooth again ; and again it is more rolling. The country soon be- 

 comes a vast undulating grassy prairie, treeless, except by some stream, 

 or large lake. There are many lakes and marshes, but some of them 

 are without a tree or shrub near them. The forest^ of maple, oak, 

 elm, basswood, poplar, pine, spruce, and tamarack are left behind. 

 The shores of Minnevvauken, or Devil's Lake, are, however, well tim- 

 bered. The species of plants are most df them western. Though 

 we have crossed no mountain range, desert, or large body of water, 

 we have suddenly entered another floral region. The absence of the 

 eastern trees and their attendants is especially noticeable. It is true 

 that some of the trees of the Mississippi Valley ascend the Missouri 

 River and its tributaries to various distances ; but the sycamore, 

 tulip-tree, hickory, basswood, maple, and other deciduous trees, one by 

 one, gradually die out to the northward and westward. The oaks and 

 elms ascend farther, and diminished in size, reach far westward on some 

 of the smaller streams. Cottonwoods and willows, though in part of 

 different species, extend to the mountain region and there mingle 

 with evergreens and other western trees. 



Very little of the rock older than the drift is exposed in this 

 part of the state, but glacial material covers nearly every part of the 

 country. If one goes westward on the Great Northern, these condi- 

 tions prevail far westward into Montana. On the Northern Pacific 

 they end at the Missouri River. Glacial drift is found west of the 

 river, but much has been removed by erosion, and the streams expose 

 older rocks. 



From the Missouri River to the Little Missouri Bad-lands. 



The Missouri River near Bismarck is a broad, muddy stream, inter- 

 rupted and broken by bars of mud and sand, bordered by muddy flats, 

 and fringed with belts of timber, or shrubbery. On one side are high 

 bluffs of soft rock, which are of Cretaceous, or Early Tertiary age. 



West of Mandan the railroad follows the valley of Heart River for 

 a short distance and then a branch called Sweet Brier Creek. The 

 streams are fringed with cottonwood, elm, choke-cherry, buffalo -berry, 

 wolf-berry., and other trees and shrubs. The bluffs on the side 

 of the valley are peculiar in shape ; some are green with vegetation 

 and some are bare. They are in places scattered over with glacial boul- 

 ders. The country-rock is usually soft with occasional harder bands. 



I 



