How exciting! A former student got a job with the Park Service and is now based at Aztec Ruins in New Mexico. He travels to other parks in the SW and is sending me cards with messages about his adventures, training activities etc.
The Chaco culture was developed by ancestors of today's Pueblo who hunted and farmed a thousand years ago, transporting stone from great distances to build their towns. They managed local water supplies but long drought periods led to economic and social instability. Eventually the people moved and resettled.
This card's text says "This view of Kin Kletso is from the Pueblo Alto Trail. Built in two stages from AD 1125-1130, it is a classic McElmo style pueblo with rooms organized into a compact rectangle with no plaza."