The greatest period of occupation of Hidden Valley must have begun sometime during the fifteenth century. It was to last about a hundred years. With the beginning of this Great Period, the period in which Puwige and all of the talus houses were most likely built and occupied, there certainly must have been some social or ceremonial organization similar to that in the modern pueblos. There were likely two moieties. The dual system where every person in the village belonged to one of two kivas—either Turquoise or Squash, or, Winter or Summer respectively. Presumably a baby born in the winter belonged to the Turquoise kiva. If it was a patrilineal society then the individual might have belonged to the same kiva as his father. Who knows but that it was a matter of personal choice? Each kiva, Turquoise or Squash, had a ruler or cacique whose word was absolute. He was the father of the village to whom villagers looked for guidance and his appointment was for life. The moieties were under the spiritual guidance of the two town chiefs who were responsible for the welfare of the people. An important office was that of cacique. He had been chosen because of his thorough knowledge of chants, sacred rituals, ceremonial procedure and prayers. No one doubted the word of the cacique. And all Indians owed duties to their respective kivas. Although the groups, Turquoise and Squash, were in opposition they also depended upon one another for the common good of the pueblo. If the dual system was in vogue at Tyuonyi, there must have been two kivas to support it. A peculiar thing, it seems, took place here. At least one tribal kiva was built and was in use before the Great Period of occupation came along. It was a large structure forty-two feet in diameter. Sixty Indians could have crouched down around the inside against the wall. Indian men, years before, excavated a large concave depression in the side of a hill a hundred yards or so down the Canyon from Puwige. Days and days were required to bring in thousands of cobble stones. They labored untiringly. They brought them from the river and they brought chunks from the cliff. Around this deep concave depression which they had laboriously scooped out of the earth with broken pieces of pottery, sticks, flat stones and whatever else they had to work with, Indian men laid stone after stone of this volcanic tuff in crude mortar. They laid a wall ten feet thick. It required thousands of the unworked stones to line this deep pit. It was a circular affair and was their way of creating a semi-subterranean chamber when they did not know how to lay single thickness masonry walls with fashioned blocks.