Love all the mountain ranges in the West because there are so many interesting rock formations and I always think of my junior high science teacher, who talked about the differences between the Sierra Nevadas and ranges in the East like the Blue Ridge.  "Basically," he opined, "the Blue Ridge mountains are just a whole lot older, so there's been more erosion and more stuff growing on them.  The Blue Ridge mountains are just old and worn down... kinda like a couple that has been married fifty years." 

I'm guessing there was a story behind that, but at fifteen years old, I didn't have the guts to ask.