6 FIELD OPERATION'S OF THE BUREAU OF SOILS, 1919. 



south-central part the topography gradually becomes more rolling, 

 and in the southeastern part the table is so dissected and broken that 

 only the sharp, narrow divides and small, flat hilltops remain as its 

 original surface level. The northern edge of the table is bordered 

 by a steep escarpment, ranging in width from one-eighth mile to 

 about 2 miles. It has an average drop of about 300 feet and is 

 steepest near the edge of the table, where it often forms cliffs and 

 vertical walls, and becomes less pronounced near its base, where it 

 flattens out gradually into the Pumpkin Creek Valley. 



The Pumpkin Creek Valley comprises about 40 per cent of the area 

 of Banner County. It is widest in the northwestern part, where it 

 extends across the north county line into Scotts Bluff County from 

 the base of the escarpment on the south. In the eastern part it has 

 an average width of about 6 miles. The valley is bounded on the 

 north by the southern escarpment of Wild Cat Ridge, which extends 

 diagonally across the northeastern part of the county. 



Pumpkin Creek flows near the northern edge of its valley. Its 

 flood plain, which lies from 1 to 3 feet above the stream channel, 

 varies in width from a few rods to about one-fourth mile. The sur- 

 face is generally flat, though modified in places by slight depressions. 

 Bordering this flood plain and extending for short distances up the 

 larger laterals is a strip of terrace or bench material having an 

 average width of about one-half mile. The surface of this bench lies 

 fi'om 8 to 10 feet above the stream channel and about 5 feet above the 

 flood plain. It has a flat to gently undulating topography, with a 

 gentle slope down the valley and toward the stream channel. The 

 break between the edge of the terrace and the flood plain is marked 

 by a rather short, steep slope. 



The land slopes from both sides of the terrace to the edge of the 

 escarpments bordering the valley. The valley slopes on the south 

 side of Pumpkin Creek and those in the northwestern part of the 

 county, where the land slopes eastward, are long and gradual. On 

 the north side of the stream they are relatively short and steep. The 

 topography of the slope land presents a variety of features. It 

 ranges from almost flat to rolling. The drainageways have narrow, 

 shallow valleys, and the areas between them are relatively smooth. 

 In a few places occur low, rounded gravel covered hills and ridges 

 representing remnants of old colluvial and alluvial fans, which, in 

 times past, have been built of materials washed down from the 

 adjoining uplands, deposited on the valley slopes, and subsequently 

 eroded until only small areas remain to indicate their former pres- 

 ence. 'More recent colluvial fan material which has been subjected 

 to considerable erosion since its deposition and now has a gently 

 rolling to rolling topography occurs extensively on the lower valley 



