_Feature 15a._--This was 10 by 10 feet with an average depth of 4 to 8 inches. Four inverted metates, additional metate fragments, manos, core tools, and a single fragment of a slate pendant. In the southeast portion were 12 symmetrical stream cobbles of different sizes. This latter aggregation is of interest. The almost perfect symmetry of the stones suggests selection, and the physiographic location of the Tank Site implies such stones must have been transported to it. None shows any evidence of utilitarian use, and in the light of present knowledge the existence and function of such objects cannot be explained. _Feature 15b._--Badly weathered, fragmentary metates; altered "lumps" of sandstone; manos; and core tools. Three small pestles were found near association. _Feature 15c._--Inverted, killed, sandstone metate; sandstone slab; and core tools. Burial 11 was in close proximity, but owing to its badly disturbed condition, no positive association could be made with the feature. _Feature 15d._--Metates; altered sandstone blocks; core tools; manos; and fragments of human leg bones. _Feature 16._--Disintegrated, pitted metate and fragments of 2 other metates; mano fragments; core tools; unworked stone; and unidentifiable fragments of human bone. _Feature 17._--Characterized by a number of symmetrically water-worn cobbles. Contrasts with other features wherein metates, manos, cores, and irregular, unutilized stones predominate. Fragmentary metates, manos, and core tools were also present, as were 2 segments of human femora. _Feature 18._--Badly weathered, inverted, deep-basin metate in near association to symmetrical sandstone cobble containing a ground depression. The latter may represent the initial stage of mortar manufacture, though the smoothness and regularity of the depression surface somewhat invalidates the idea. _Feature 19._--Metates (deep basin, shallow basin, and slab); mano fragments; scraper planes; core hammerstones; and fragments of human femora and tibiae. The deep-basin metate was right side up, in contrast to the usual inversion. _Feature 20._--Deep-basin metate with associated metate fragments; carbon-smudged blocks of disintegrated sandstone core tools; and sections of human femora. _Feature 21 (pl. 18, b)._--Large, shallow-basin metate and fragments of 2 others; 2 large, reworked, granite boulders; 3 blocks of highly decomposed sandstone; core tools; mano; and fragments of human femur. _Feature 22 (pl. 20, b)._--Deep-basin metate; 2 slab metates and 3 metate fragments; chunks of altered sandstone; core tools; and a large, chert blade.