Several small cliff-houses occur in Sand Canyon, one of the northern tributaries of the McElmo. Stone Arch House, here figured (pl. 6, _a_), so-called from the eroded cliff (pl. 4, _b_) near by. It is situated in the cliff, about a mile from where the canyon enters the McElmo Canyon near Battle Rock. Abundant piñon trees and a few scrubby cedars grow in the low mounds of the talus below the ruin, near which, on top of a neighboring rock pinnacle, still stand the well-constructed walls of a small house (pl. 4, _a_). DOUBLE CLIFF-HOUSE The formerly unnamed cliff-house shown in plate 8[37] is one of the best preserved in Sand Canyon. It consists of an upper and a lower house, the former situated far back in the cave, the latter on a projecting terrace below. Unfortunately it is impossible to introduce an extended description of this building as it was not entered by the author’s party, but from a distance the walls exhibit fine masonry. It is unique in having double buildings on different levels, an arrangement not rare in a few examples of cliff-dwellings on the Mesa Verde. As shown in plate 8, the character of the rock on which the lower house stands is harder than that above in which the cave has been eroded. The upper house is wholly protected by the roof[38] of the cave and occupies its entire floor. The lower house shows from a distance at least two rooms, the front wall of one having fallen. [36] Sun Temple, however, is a seeming exception and follows the McElmo rule of proximity; several large cliff-dwellings occur under the cliff on which this mysterious building stands. [37] Taken from a point across the canyon, the only one from which both houses can be included in the same photograph. [38] For a good example of cliff-houses at different levels, see Cliff-Dwellings in Fewkes Canyon, Mesa Verde National Park, Holmes Anniversary Volume. From a distance the walls of both the lower and the upper house seem to be well preserved, although many of the component stones have fallen to the base of the cliff. SCAFFOLD IN SAND CANYON One of the cliffs bordering Sand Canyon has an inaccessible cave in which is an artificial platform or lookout shown in plate 7, _a_. Although this structure is not as well preserved as the scaffold in the neighborhood of Scaffold House in Laguna (Sosi) Canyon, on the Navaho National Monument, it seems to have had a similar purpose. It is constructed of logs reaching from one side of the cave to the other supporting a floor of flat stones and adobe. Its elevated situation would necessitate for entrance either holes cut in the cliffs or ladders. UNIT TYPE HOUSES IN CAVES