I lived at the Pueblo Alto Trading Post (Run by a man named Tanner who flew a Cessna 175 in and out of the area from Farmington) in 1967-68. I played football with a group of missionaries in what was then called the Chaco Canyon's Ruins (we actually played in the wash on the sand).
At that time we say what appeared to be mearly inches of what must have been tops of walls at that sight.
I do remember that up higher on the north side, there was a ledge so to speak - where a huge water basin was shaped out of the rock (approx 15-25 ft wide by no more than 4-8 ft deep. If you remember this "oddity" we are talking about the same sight.