NO. 10 NEBRASKA ARCHEOLOGY STRONG 3I 



division termed the Interior Plains.'^ The Interior Plains, however, 

 are divided into two provinces within the State. The first of these 

 is the Central Lowland, of which only the eastern fringe extends 

 into Nebraska, including a rather uniform glaciated strip about 60 

 miles wide extending the length of the State just west of the Missouri 

 River. In Kansas, and again in South Dakota, this strip is clearly 

 set ofif from the Great Plains proper by an east-facing escarpment 

 which in Nebraska is lacking owing to the thick mantle of loess. The 

 line, however, follows the western edge of the glacial drift through- 

 out the State. Characteristically, the Central Lowland consists of 

 maturely to submaturely dissected till plains which are relatively low 

 and flat, with streams not far above their base level. To the west 

 there is usually a rise of a few hundred feet, beyond which the streams 

 are actively dissecting, but in Nebraska, as just stated, this clear sur- 

 face indication does not occur. The greater part of the State, how- 

 ever, falls into the Great Plains province, owing to the active dis- 

 section of the streams and the pleateaulike character of the central 

 and western terrain. This terrain has a marked slant to the east, 

 which reaches its highest point of 5,250 feet on the western border 

 in Kimball and Banner Counties and its lowest dip in the southeast 

 corner near Rulo. where the altitude is only 900 feet. There are three 

 sections or subdivisions within the Great Plains province which either 

 include large portions of or touch upon Nebraska. Three- fourths of 

 the State, including the central and western sections, is included in 

 what the Fenneman classification terms the High Plains. This large 

 area is the remnant of the originally smooth plain caused by Tertiary 

 deposits which once stretched from the mountains to the eastern edges 

 of Kansas and Nebraska. Although it has been somewhat dissected 

 by streams, the intervening areas are truly residual plains. To the 

 south is an area from which the Tertiary mantle has in large part been 

 eroded and which is dissected by streams but not yet reduced to the 

 low level of the Central Lowland province. This is considered as the 

 Plains Border section of the Great Plains province and, in Nebraska, 

 comprises a narrow strip along the southern border between Furnas 

 County on the west and Thayer County on the east, extending hardly 

 more than 60 miles north from the Kansas-Nebraska line. The Mis- 

 souri Plateau, comprising the third division or section of the Great 



^' For the main physiographic divisions of Nebraska see Fenneman, 1928, 

 PP- 309-322 and map. For the specific physical geography of Nebraska, Condra, 

 1906, and Condra and Keyser, 1908; and for biotic zones and descriptions, 

 R. H. Wolcott in Shelford, 1926, pp. 519-524. The present section has in the 

 main been summarized from these sources. 



