Went to Mesa Verde last year but thankfully was not bombarded by too much eco-babble.
The cliffside structures would have been inconvenient for day to day living so there being located as a defensive decision makes sense.
As a WAT-—wild ass theory—— I wondered that since this forting-up in the Southwest occurred congruent with the Mongol era if maybe some North Asians had crossed over and ended up attacking our earlier residents.
I see violent era in the near future
I suppose it’s possible. The Mongols made two attempts on Japan, both driven off by tyhoons, and some of the damaged ships could have drifted a long way.
But Mesa Verde is a loonng way from the coast and it’s hard to see why they’d hike all that way to attack people who just didn’t have that much to steal.
Also, nobody’s ever found any evidence of metals, recurved bows or other technologies the Mongols were perfectly familiar with.