Horseshoe House (pl. 23, _c_) stands on the north edge of the canyon (fig. 12, 1), having its straight wall on the south side, as is usually the case, the well-preserved north side being curved. The northeastern corner still stands several feet high. The southeastern corner formerly rested on a projecting rock, which recalls the cornerstone of Sun Temple. The masonry of most of the southern segment of the enclosed circular room or tower has fallen down the cliff. There does not appear to have been a doorway on the south side, and there is not space for rooms on this side on account of the nearness to the edge of the cliff. While the form (fig. 13) of Horseshoe Ruin recalls that of Sun Temple, in details of room structure it is widely divergent. The length of the south wall, or that connecting the two ends of the horseshoe, is 30 feet, its width 27 feet; the highest wall on the northwest side is 12 feet. Figure 13 shows the arrangement of the rooms and the mutilation of the south wall of the ruin. The distance between the outer and inner concentric walls averages 4 feet; the circular room is 17 feet in diameter. In the same cluster as Horseshoe Ruin (pl. 24, _a_) there is another well-made tower (fig. 12, 4), constructed on a point at the entrance to the canyon, and below it in a cave are well-preserved walls of a cliff-dwelling. [Illustration: FIG. 13.—Ground plan of Horseshoe House.] A short distance due north of Horseshoe House, at the head of a small canyon, a tributary of Bridge Canyon, there are two large pueblos and a round tower. The pueblos are mentioned by Prudden, who gives a ground plan which indicates an extensive settlement. TOWERS IN THE MAIN YELLOW JACKET CANYON Of the several towers and great houses of the main Yellow Jacket Canyon two may suffice to show their resemblance to those in Square Tower Canyon. The two towers considered belong to the D-shaped variety, the straight wall, as is almost always the case, being on the south side. DAVIS TOWER Mr. C. K. Davis, who lives not far from the Yellow Jacket Spring, conducted the author to a tower of semicircular ground plan (fig. 14) near his ranch. This ruin (pl. 26, _b_), is situated on a rocky ridge on top of the talus halfway down to the bottom of the canyon, on its right side. LION (LITTRELL) TOWER[51] This tower (pl. 29, _b_) is built on a bowlder situated in Yellow Jacket Canyon a mile from Mr. Littrell’s ranch and about 5 miles south of the Yellow Jacket post office; approximately 20 miles from Dolores, Colorado. Its ground plan (fig. 15) is D-shaped, the lower story being divided by partitions into four rooms. The wall of the middle room seems to be double, or to have been reenforced. It measures 40 feet on the straight side, the highest wall being about 25 feet above the base. The foundations rest on the irregular surface of a bowlder to which it conforms. [51] This tower is reputed to be the home of a mountain lion, hence the name Lion House.