22 FIELD OPERATIONS OF THE BUREAU OF SOILS, 1912. 



The soils of the area which are recognized as derived wholly or 

 in part from ice-laid material are those of the Rockford and the 

 Parkdale series. The Rockford series is represented by two types, 

 viz, the Rockford stony clay loam and the Rockford clay. The 

 former includes an eroded phase. The typical soil occurs only 

 in the Hood River Valley, though a small body of the eroded 

 ])hase borders the Columbia River on the Washington side. The 

 type occupies gently undulating or sloping areas slightly elevated 

 above the adjacent soils of the valley floor and carries an abun- 

 dance of glacial bowlders. The Rockford clay covers only an 

 inextensive area on the western side of the Hood River Valley 

 between the Rockford stony clay loam and the higher lying residual 

 soils of the Underwood series occupying the mountain slopes. Some 

 undifferentiated colluvial and alluvial foot-slope material from the 

 higher mountam soils is included with this type. Rock or gravel is 

 not abundant in the soil, but glacial bowlders occur in small quantities, 

 and are commonly visible along the courses of the minor stream ways. 

 The soils of the Rockford series are of reddish-brown color and are 

 underlain by reddish-brown to yellowish subsoils, overlying deep, 

 compact deposits of glacial till. 



The Parkdale series is represented by a single type, the Parkdale 

 loam. This occurs only in the southern part of the area as a dissected 

 plain with a very noticeable slope to the south. The deeper subsoil 

 and substratum is a rocky glacial till, but this is covered by a mantle 

 of finer material. The area occupied by this t}^e resembles in 

 topographic features a glacial outwash plain, and the finer supei'ficial 

 soil material may consist predominantly of stream-laid glacial 

 outwash material of fine sandy and silty texture or of thoroughly 

 weathered material derived from the underlying drift. Streams 

 traversing the plain have cut narrow, rocky gorges into this material 

 and often deeper into the underlying bedrock. The soil is of brown 

 or light-brown color, often with a reddish tint, and usually contains 

 a noticeable quantity of fine pellets. The subsoil is a light-brown to 

 mottled gray and brown silt loam in which the percentage of pellets 

 is generally less than in the soil material. 



Of the water-laid sedimentary soils of the area, the most extensive 

 and important is the Hood silt loam, winch, like the Parkdale loam, 

 is the only representative of its series recognized in the survey. The 

 origin of this type is not definitely known, but from the depth, 

 uniformity, and fineness of the material it appears to be a deposit 

 laid down in bodies of quiet water, and has probably been derived 

 from fuie glacial material. This type is one of the most important 

 soils in the area, and upon it are found the larger number of the 

 productive orchards in these two valleys. This soil is light gray or 



