No more interesting question in southwestern archeology awaits an answer than the query: What became of the former inhabitants of the Chaco ruins, one of the largest clusters of deserted buildings in New Mexico? Like the cliff dwellers of the Mesa Verde, their former inhabitants have disappeared and left no clue as to where they went, the date of their occupation of the ruins, or their kinship with other peoples. Existing legends relating to them among supposed descendants who are thought to live in modern pueblos are fragmentary and knowledge of their archeology is defective. The Hyde Expedition made an extraordinary collection of artifacts from Pueblo Bonito, the largest and formerly the best preserved ruin of the group, but the excavations there have yielded little information on the kinship of its inhabitants. Until we know more about the Chaco Canyon ruins we are justified in the belief that there still remains a most important problem for the archeologist to solve. In seeking the prehistoric migration trail of the Hopi before they came to Fire House, the author examined ruins near Crown Point identical with those of the Chaco Canyon. There are in fact two ruins within a few miles of the Crown Point Indian school, one of them known among the Navaho Indians as Kin-a-a (the name of the other unknown to the author), which are structurally members of the Chaco series. The ground plan of the largest, Kin-a-a,[7] is rectangular and was apparently oriented north and south, the walls on the north side being the highest and best preserved and those on the south possibly terraced. On the south side remnants of a court or enclosure surrounded by a low wall can still be detected. The ruin is compact with embedded kivas and measures approximately 150 feet long by 100 feet wide, the north walls rising in places to 50 feet, showing good evidences of five stories, one above the other. The high walls reveal rooms of rectangular shape. Situated midway in the length of the north wall (pl. 4, _a_, _b_, _c_) is a circular chamber like a kiva on the ground floor, with high walls about it. The recesses between the wall of the circular room and the rectangular wall enclosing it are solidly filled in with masonry, a mode of construction adopted in the great ruins of the Chaco Canyon. The kiva of Kin-a-a (pl. 5, _a_, _b_), like those of the great building of the same canyon, are built into the mass of rooms and not separated from them as in the modern pueblos, Walpi, those of the Rio Grande, and the ruin of Sun Temple on the Mesa Verde. This separation of the kiva from the house mesa is regarded by the author as a late evolution, being unknown among the cliff dwellers, and very rare in pueblo ruins possessing ancient characteristics. A union or huddling together of sacred and secular rooms is characteristic of the period when each kiva was limited to the performance of clan rites, the separation of the kiva from secular rooms marking the development