Mount Rainier, seen from 21,000 feet coming into Seattle on August 30, 2013.
Leaving Portland on September 9. I don't know my Cascades that well, but this one seems to be missing it's top, so I'm going to guess Mt. St. Helens.
The mountain on the horizon looks to me like Rainier, again, but without the sea of clouds observed on the 30th. The closer one, then, surrounded by a skirt of clouds, is most likely Mt. Adams. Another view below.
Other than the first view of Rainier, I'm not sure about any of the other mountains. If I'm wrong, I would appreciate any corrections. If I'm right, validation is always appreciated.