Mountain flying is more than just altitude. Somebody told me that you can't outpower the moutains, but you can outsmart them - meaning that a good plan and strategy how, when and where to fly are important. The rule of a thumb I'm hearing around the Rockies is that you have to double the highest peaks if you don't want to feel the effects of the mountains. Not many pilots have this luxury (not to mention that summer effects and plane's age can lower the ceiling altitude substantially). Definitely and for sure check with the local pilots -- they know the area the best.
I also suggest to check the following book "Flying the Mountains" by Fletcher Anderson (McGraw Hill, ISBN 0-07-141053-8)
http://www.amazon.com/exec/obidos/tg...glance&s=books