Douglass: A Geological Reconnaissance. 267 



III. The Southwestern Portion of NortJi Dakota, west of the Mis- 

 souri River, consisting of bad-lands, and high prairies, over portions of 

 which are scattered buttes, hut no extensive glacial moraines. The 

 whole region shows elevation and quite extensive erosion, but the strata 

 are nearly horizontal. Most of the rock exposed is of Tertiary age. 

 There is some glacial drift, but it is not a prominent feature. In places 

 some timber grows along the streams. 



IV. The Eastern Portion of Montatia. — An elevated plain, where 

 there has been not only extensive uplifting, but in places considerable 

 tilting of the strata, which, combined with erosion, has brought to the 

 surface rocks from those of Judith River age, or earlier, up to those of 

 the Lower Eocene. Near the mountains are local outcrops of rocks 

 reaching down to the Jurassic or Lower Cretaceous. The different 

 formations apparently increase in thickness, and the number of their 

 distinct divisions becomes greater as the mountains on the western 

 boundary are approached. The timber is confined principally to the 

 valleys of streams and to the higher portions in the vicinity of the 

 mountains, and consists principally of cottonwoods, willows, and coni- 

 fers ; though in some places along the streams there are other hardy 

 trees. There are isolated mountain-uplifts in the western portion, 

 where Paleozoic rocks are exposed, and the conditions are similar to 

 those in the mountainous region to the westward. 



V. The Mountainous Region of Western Montana. — This is a region 

 of extremely varied physical and topographic conditions, as well as of 

 complex geological features. The rocks, representing all the geolog- 

 ical eras from Archaean to the present time, lie in all positions from 

 horizontal to perpendicular. The country has the appearance of hav- 

 ing been for ages the battle-ground of geological forces, when the vast 

 region to the eastward was comparatively quiet. On many of the 

 mountain ranges grow forests of conifers, while along the streams and 

 in other favorable localities are hardy deciduous trees, such as willows, 

 cottonwoods, alders, mountain maples, hawthorns, etc. 



VI. The Northern Portion of Eastern IdaJio. — A land of desert 

 plains, bordered on the north by mountains and foot-hills, in sections 

 of which are parks and forests of evergreens, especially in the eastern 

 portion. The rocks are of igneous origin. 



The geological conditions and physical characters of Division I. 

 have been recorded in the splendid final reports of the Geological 

 and Natural History Survey of Minnesota. The geology of the 



