38 FIELD OPERATIONS OF TUE BUREAU OF SOILS, Htl2. 



to be of auy importance. The pellets conspicuous in most of the 

 other members of the Wind Kivor series are wantin<r- 



The type occm*s on the nearly smooth, sloping floor of the iii)i)cr 

 White Salmon River Valley, in the extreme northern part of the 

 area, and as a single small bod}' in the Hood Iliver Valley, about 

 2 miles west of the to^vn of Ilood River. 



The drainage is usually good to slightly excessive. The uuder- 

 hiiig rock hi the White Salmon River Valley consists of a sheet of 

 basaltic lava of recent date, the sm-facc of which, over much of the 

 area covered by tliis soil type, is marked h^^ irregular mounds of 

 protrudmg rock vrith mtervenhig depressions jiartially fiUed with soil 

 material. The u-regularities of surface have doubtless been caused 

 b}' steam, the mounds often appearmg as steam blisters from a few 

 feet to a few rods m diameter. Owmg to this structure excessive 

 subdrainage is a general characteristic of the soil t}'po, and, miless 

 there is a considerable depth of soil to act as a reservoir for moisture, 

 irrigation or raui water rapidly percolates below the reach of ])lant 

 roots. 



The soil is apparently of alluvial origui and without relation to the 

 underh-ing lava. It is not, however, m all respects tA'pical of the 

 Wind River series, and fm-ther field studies may warrant placmg it 

 m a distinct series. The material is apparently derived mainly from 

 basaltic rocks, and it seems probable that foUowhig the filling in of 

 the vaUey depression by the flow of lava m the Wliite Salmon River 

 Valley, a stream, now represented by the White Salmon River, fol- 

 lowed a course across the lava and deposited a mantle of sedhnent 

 derived from the material eroded from the soils and rocks on the 

 southern and southwestern slopes of Momit Adams. In the Hood 

 River Valley the soil occupies a small area of elevated terrace and is 

 a remnant of an old elevated plaui of the Columbia River. It is not 

 unlikely that some material derived by weathering of the miderljing 

 basaltic rock has been mixed with th(^ alluvium, but the basalt where 

 exposed shows little c\ddence of wcathermg. 



The original forest growth on this type consisted of phie, witli but 

 little undergrowth of brush or grass. The stand of pine was scatter- 

 ing, on account of the scanty supply of moistm'e, in marked contrast 

 to the heavily forested and brush-covered slopes of the bordering 

 mountams, where the de])th of the soil and the presence of moisture 

 are favorable to the growth of trees. 



On account of the shallowness of much of this tyi)e, the area of 

 cultivable land is small. It is only hi thost^ ])arts where the soil is 

 of considerable dci:)th that any cultivation has been attempted, and 

 then only with the aid of nrigation. Hay crops, such as native 

 grasses, aUaKa, and clover, do well and are grown for the feedmg of 

 work anhnals or thxiry stock. Some fruit, includmg apples, crab 



