Only to Americans suffering from advanced couch potatoitis. If you examine the map, the elevations are from 1,000 meters to 1,500 meters. Not enough to stop anyone from walking through, but more than enough to make construction costs skyrocket.
The Rockies are a far less formidable barrier than the mountains of Afghanistan. And neither the Mujihaddeen or the Taliban ever found the mountains of Central Asia to be any sort of significant barrier to their movement.
Yeah right, spend a day at the local supermarket and tell me what kind of physical condition the folks that can't or refuse to speak a single word of English and are buying their groceries with foodstamps are in?
They look like they'd be great mountain climbers to me.
At least they could camouflage themselves as larger than average boulders. /sarcasm