NOTES ON FOREST CONDITIONS IN THE CENTRAL 

 SIERRA NEVADAS. 



W. A. Rockie, '14. 



The following notes were collected in the east central part 

 of California, from Lake Tahoe northward to the south fork of 

 the Feather River which drains the Sierra Valley. The east 

 boundary of this area is the desert while the 5,000 foot contour 

 line may be roughly considered the western boundary. The area 

 comprises the major part of the Tahoe National Forest and the 

 forest conditions are typical of the central portion of the Sierra 

 Nevada Mountains. 



The main range has a general northwesterly direction 

 through the center of the region. The altitude varies from 

 nearly 5,000 feet at both the eastern and western borders to 

 elevations of from 7,000 to 9,000 feet along the divide. The 

 canyons and their lesser tributaries are generally of a steep and 

 precipitous character, and vary in depth from 500 to 2,000 feet 

 or more. The east slope, being the escarpment of the huge 

 Sierra upheaval, is characteristically steeper and shorter than 

 the west slope which has a gradual incline. Nearly all the peaks 

 consist of an easily decomposed tuff breccia, resembling a poorly 

 made cement mortar, underlaid with resistant granite of a great 

 thickness. Since this formation overlies the granite, the soil 

 from the upper tuff-breccia rock is carried down by gravity and 

 does much to cover what would otherwise be bare granite slopes. 

 Often on the uppermost slopes of the peaks and ridges the soil 

 is too shallow or unstable to support forest growth. On the 

 lower slopes only local areas of barren rock exist. The majority of 

 these slopes, however, have a sufficient soil cover to support a 

 dense forest growth. The type of soil found here is generally very 

 gravelly in texture, being much coarser and more unproductive 

 immediately below a bare rock area. Several flat mountain val- 

 leys or meadows were found where the soil was a very deep, 



