Figure 5 . — Mi Iter 

 Creek drainage 

 showing five 

 major vegeta- 



tion zones. 



Because this zone includes the harshest sites and areas of least vegetation, it 

 was the zone trenched for this study. The fifth, or oakbrush {Quercus gambelii) zone, 

 occupies more than 50 percent of the drainage. This zone ranges from sparsely veg- 

 etated dry slopes where mountain mahogany {Ceroooarpus ledifolius) also is common to 

 wetter sites, areas covered with dense oakbrush intermixed with maple {Aoer g lab rim) . 



The Miller Creek drainage tends more toward forest and is generally much more 

 densely vegetated than Halfway Creek drainage (fig. 5). Here, subalpine fir [Abies 

 lasiooarpa) occupies much of the upper middle part of the drainage, the ceanothus zone 

 on the Halfway Creek drainage. Fir is interspersed with clones of quaking aspen. 

 Because of the exposure and the wetter site, aspen is also found well down into the 

 bottom of the drainage in the mixed browse zone. Sagebrush grows along the tops of 

 both drainages. An additional zone, the grass-forb, occurs on those areas where 

 snowbanks persist late into the summer. 



6 



