After discovering Cliff Palace and Spruce Tree House, Richard Wetherill and Charles Mason returned to their camp. The next morning they started off to visit Spruce Tree House, which only Richard had seen the day before. As they rode across the snow covered mesa they misjudged their direction and bore too far to the south. Coming to the rim of a deep canyon they found, not Spruce Tree House, but another large cliff dwelling.

Although not as large as the two they had found the day before it was still much larger than any they had seen previously. The outstanding feature of the ruin was a tall square tower, a four-story structure that rose against the cliff. Because of it they later named the ruin Square Tower House.

The two men now began to realize the importance of their discoveries. During the past few years they had seen many small ruins along the Mancos Canyon to the south. Now they had pushed up the canyons to the north and in the space of two days had found not only the ruin Acowitz had called the “greatest cliff dwelling,” but two more large ruins. As they sat on their horses above Square Tower House they could see that off to the north and west were many more canyons. Surely more of the mysterious structures awaited discovery.