Above the tree line, Mt. Hood is a big pile of rocks and fine volcanic ash. The fine sand makes for strenuous hiking, especially when combined with the thinner air at this elevation. The open skies here can be good for raptors. On this day I just saw two Red-tailed Hawks, a Prairie Falcon, and several Common Ravens.
The Pacific Crest Trail runs through areas with a few more trees. Dark-eyed Juncos, Golden-crowned Sparrows, Pine Siskins, Ruby-crowned and Golden-crowned Kinglets, and Yellow-rumped Warblers were the most common species in this habitat. Nala would stop and rest in every little patch of shade she came to. She has a lot more stamina when she is swimming than she does when hiking in hot dry habitats.