From Durango, take 160 West until you see signs for Mesa Verde. It is about 70 miles from Durango. To get a feel for the sophistication and magnitude of the dwellings, take the "Loop Road" to view the dwellings from afar and then begin to explore. The best is called "Cliff House!"
In the winter, you only get to see any of the "Houses" if the snow is removed from the Loop Road, and then the only House you can visit is the Spruce House. Having visited in both the winter and the summer, I would recommend the Fall when the number of tourist are down and the temperature is not either freezing or scalding. I have seen photos of SOuthern Colorado in the Fall with the swaths of golden colored leaves of the aspens -- Gorgious!
Around 1200 AD, a group of Ntive American carved out ledges and caves from the sheer cliffs of what today is the Mesa Verde National Park. This particular dwelling is just part of "Spruce House" and was the only cliff dweling accessible to tourits in the winter. Note the sheer magnitude of the overhanging rock. Sometimes when I am having a depressive episode, I feel as if this pieve of rock is pressing down on my shoulders!