In the mountains of San Gabriel, overlooking the lowland vines and fruit groves, Mother Nature is most ruggedly, thornily savage. Not even in the Sierra have I ever made the acquaintance of mountains more rigidly inaccessible. The slopes are exceptionally steep and insecure to the foot of the explorer, however great his strength or skill may be, but thorny chaparral constitutes their chief defense. With the exception of little park and garden spots not visible in comprehensive views, the entire surface is covered with it, from the highest peaks to the plain. It swoops into every hollow and swells over every ridge, gracefully complying with the varied topography, in shaggy, ungovernable exuberance, fairly dwarfing the utmost efforts of human culture out of sight and mind.
~ From Steep Trails by John Muir. Chapter 11, The San Gabriel Mountains.