46 FIELD OPERATIONS OF THE BUREAU OF SOILS, 1919. 



vated crops, and it is all included in pastures on which beef cattle 

 and horses are grazed. The native vegetation consists of a sparse 

 growth of sand grass, stipa, grama grass, and blackroot, the last a 

 sedge. 



It is difficult to estimate the value of this soil, as it is generally 

 sold in connection with other types. Where it comprises a consider- 

 able part of the farm land, however, it greatly lowers the selling 

 price. 



BRIDGEPORT LOAMY FINE SAND. 



The Bridgeport loamy fine sand in Banner County has the same 

 color, texture, structure, and other characteristics as that mapped 

 in Morrill County, joining on the east. The surface soil is a loose, 

 incoherent, light-brown to brown loamy fine sand, 8 to 10 inches 

 deep. A small amount of organic matter in the upper 6 inches gives 

 this layer a slightly darker color than that of the material below. 

 It is this organic matter that gives the type its loamy character. 

 Scattering gravel are found on the surface. 



The upper subsoil is a light grayish brown to gray loamy fine sand 

 to fine sand, and the lower subsoil- from about 24 inches down is a 

 loose, incoherent, gray to light-gray fine sand. Both soil and sub- 

 soil contain relatively large percentages of very fine sand. The type 

 is low in organic matter and is not easily built up on account of its 

 loose, open structure. The lower subsoil is calcareous. This type 

 differs from the Valentine loamy fine sand, chiefly in the gravel 

 scattered over the surface and in the calcareous nature of the lower 

 subsoil. 



The Bridgeport loamy fine sand is an extensive soil in Banner 

 County. It occurs in scattered areas over the colluvial slopes, on 

 both sides of Pumpkin Creek. The largest developments lie on the 

 south side of the stream. One body was mapped on the north side 

 of Wild Cat Ridge, in the northeastern part of the county. The 

 areas vary in size from a few acres to 4 or 5 square miles. They 

 are generally uniform in character and little spotted with areas of 

 other types of soils. One of the larger bodies lies on the north side 

 of Pumpkin Creek, in the northern part of the county. A much 

 smaller though typical area is mapped near the mouth of Indian 

 Springs Canyon. 



As with the other soils of the Bridgeport series, the type is com- 

 posed of materials that have been blown by the wind or washed down 

 by water from the adjoining uplands. Torrential rains have un- 

 doubtedly played an important part in washing down the soil ma- 

 terial. Much of the type, however, has been so modified by wind- 

 blown material that its exact mode of formation is uncertain. 



The type occupies flat to gently undulating slopes, the surface of 

 which is modified by occasional depressions and low,- rounded hum- 



