While, however, the Homolobi group of ruins is the most southerly to which I have been able to affix a Hopi name, others still more to the southward are claimed by certain of their traditions.[8] The Hopi likewise regard as homes of their ancestors certain habitations, now in ruins, near San Francisco mountains. In a report on his exploration of Zuñi and Little Colorado rivers in 1852, Captain L. Sitgreaves called attention to several interesting ruins, one of which was not far from the "cascades" of the latter river. After ascending the plateau, which he found covered with volcanic detritus, he discovered that "all the prominent points" were "occupied by the ruins of stone houses, which were in some instances three stories in height. They are evidently," he says, "the remains of a large town, as they occurred at intervals for an extent of eight or nine miles, and the ground was thickly strewn with fragments of pottery in all directions." In 1884 a portion of Colonel James Stevenson's expedition, under F. D. Bickford, examined the cliff houses in Walnut canyon, and in 1886 Major J. W. Powell and Colonel Stevenson found scattered ruins north of San Francisco mountains having one, two, or three rooms, each "built of basaltic cinders and blocks of lava." These explorers likewise reported ruins of extensive dwellings in the same region made of sandstone and limestone. At about 25 miles north of the mountains mentioned they discovered a small volcanic cone of cinders and basalt, which was formerly the site of a village or pueblo built around a crater, and estimated that this little pueblo contained 60 or 70 rooms, with a plaza occupying one-third of an acre of surface.[9] Twelve miles eastward from San Francisco mountains they found another cinder cone resembling a dome, and on its southern slope, in a coherent cinder mass, were many chambers, of which one hundred and fifty are said to have been excavated. They mention the existence on the summit of this cone of a plaza inclosed by a rude wall of volcanic cinders, with a carefully leveled floor. The former inhabitants of these rooms apparently lived in underground chambers hewn from the volcanic formation. Eighteen miles farther eastward was another ruined village built about the crater of a volcanic cone. Several villages were discovered in this locality and many natural caves which had been utilized as dwellings by inclosing them in front with walls of volcanic rocks and cinders. These cavate rooms were arranged tier above tier in a very irregular way.