The resources of the prehistoric people of the Yakima Valley, as indicated by the specimens found in the graves and about the village sites, were chiefly of stone, copper, shell, bone, antler, horn, feathers, skin, tule stalks, birch bark and wood. They employed extensively various kinds of stone for making a variety of objects. Obsidian,[26] glassy basalt or trap, petrified wood, agate, chalcedonic quartz with opaline intrusions, chert and jasper were used for chipping into various kinds of points, such as those used for arrows, spears, knives, drills and scrapers. According to Spinden,[27] obsidian was used in the Nez Perce region to the east where it was obtained from the John Day River and in the mountains to the east, possibly in the vicinity of the Yellowstone National Park. The people of the Yakima Valley may have secured it from the Nez Perce. As on the coast, objects made of glassy basalt were rare here, although it will be remembered that they were the most common among chipped objects in the Thompson River region.[28] Mr. James Teit believes that glassy basalt is scarce in the Yakima region and that this is the reason why the prehistoric people there did not use it extensively. Some agate, chalcedony and similar materials were used in the Thompson River region, but while there is a great quantity of the raw material of these substances there, the Indians say that the black basalt was easier to work and quite as effective when finished. Several small quarries of float quartz had been excavated and broken up to be flaked at adjacent work shops, p. 16. River pebbles were made into net sinkers, pestles, mortars, hammerstones, scrapers, clubs, slave killers, sculptures, and similar objects, and were also used for covering some of the graves in the knolls. Serpentine was used for celts and clubs; lava for sculptures. Slate was used for ornamental or ceremonial tablets steatite for ornaments and pipes, though rarely for pestles and other objects; and impure limestone for pipes. Fragments of basaltic rock were used for covering graves in the rock-slides and in some of the knolls. Places on the basaltic columns and cliffs served as backgrounds upon which pictures were made, some being pecked,[29] others painted.[30] No objects made of mica or nephrite were found. Siliceous sandstone was made into pestles, pipes and smoothers for arrow-shafts, but the last were rare. Copper clay, white earth and red ochre were not found, but red and white paint were seen on the basaltic cliffs and Mrs. Lynch reports blue paint from a grave near Fort Simcoe (p. 117). [26] See Fig. 5 and 202-8141, p. 154. [27] Spinden, p. 184. [28] Smith, (d) p. 132 and 135 (c) p. 407. [29] See Plates XI-XIII. [30] See Plates XIV-XVI.