Before moving from Denver to Houston in 2010 I did a road trip with the wife and 9mo kid to the 4 corners area.
We hit the Garden of the Gods in Co Springs, the Great Sand Dunes, Mesa Verde, the Grand Canyon, Antelope Canyon and Arches National Park. Both camped and stayed in motels.
The poor little guy spent hours in the car seat and then in the trekking backpack. Long drives to get to those places, but it was totally worth it and he enjoyed it a bunch. My daughter wouldn't have been as keen to remain in the car seat
There is a train museum in Durango and of course amazing train rides.
I realize some of the places I mentioned are far out from your basecamp, but to us it was the only time to get to see them until who knows when. We did take a heli flight over the grand Canyon which was even more impressive from the air than at eye level.
