SOIL SURVEY OF THE EED BLUFF AREA, CALIFORNIA. 59 



canic origin, a part of which covers a considerable area in the north- 

 eastern part of the Tehama Qiiadrangie. This plain in turn breaks 

 uniformly by steep descents into the Tuscan series, and a strip about 

 one-half mile in width was included in the survey which constitutes 

 the Rough stony land of the Red Bluff area. Eastward from that 

 arbitrary boundary line, running northwest and southeast, this typQ 

 extends indefinitely as the variable, broken nonagricultural section of 

 the high plains and foothills. 



Rough stonj^ land has a surface too precipitous and roclry^ for agri- 

 culture. Its surface is strewn with great quantities of volcanic 

 bowlders, marked by rock outcrop and cut by the small canyons of 

 drainage ways (see PI. II, fig. 2). The fine-earth material consists 

 of a reddish loam somewhat like the soil of the Tuscan series, and 

 the boundary between Rough stony land and the Tuscan soils was 

 established along the line at which the rougher slopes gave way to 

 conditions favoring agriculture, so far as topography is concerned. 



A scant growth of upland oak, chaparral, and native grasses cover 

 the areas of Rough stony land. Grazing is the only purpose for 

 which it can be used. 



SUMMARY. 



The Red Bluff area covers about 326 square miles of the northern 

 extremity of the main Sacramento Valley. It consists of slightly 

 elevated treeless plains cut by small alluvial valleys and by the Sacra- 

 mento bottoms. The upland plains are sparsely settled and little 

 farmed. 



Transportation is furnished by two lines of the Southern Pacific 

 Railroad and by river steamers. Markets are found for the green 

 fruits and vegetables in the contiguous territory of northern Cali- 

 fornia and Oregon. The staples enter the world markets. 



Red Bluff' is the principal town, with a population of 3,530. Corn- 

 ing, Tehama, and Vina are other places of importance. 



The climate differs little from that of the remainder of the great 

 Interior Valley. Red Bluff has an annual rainfall of 26.33 inches. 

 The summers are hot and rainless, but not oppressive. Long grow- 

 ing seasons occur, with little damage from frost. Prevailing winds 

 are from the north. The general climate is favorable to the pro- 

 duction of a great variety of fruits. 



Agi-iculture was begun in 1852 and the area developed into an im- 

 portant grain-producing section. Decreased yields and lower prices 

 caused a shrinkage in the area so used. The dry-farmed fruit in- 

 dustry has been developed until it occupies much attention. Peaches 

 are the leading fruit. Land holdings are usually extensive, and 

 some ranches of several thousand acres occur. Some failures have 

 followed injudicious colonization. 



