Join Date: May 2010
Location: Bristol, R. I.
Bikes: Specialized Secteur, old Peugeot
You can't train for altitude. I've gone from sea level Rhode Island to the Rockies in Colorado. I would spend two nights in Durango and go for a hike to 10k feet between those sleep sessions, on one of the many trails just outside of town. It will take a week or more to become moderately used to some altitude but the short hike will help and reduce danger of altitude sickness for those who acclimatize poorly or not at all.
On our first backpacking trip to Colorado, my hiking partners Ind I spent our first night at a campground just outside of Durango. The next day we took the Duango to Siverton narrow gauge steam train to begin our hiking. That next night we slept at about 10,000 ft and all four of us had altitude induced head aches. Within a few days, we were at 12,000 feet and moving fast with with only relatively minor discomfort.