How are pictographs able to stand the test of time?
The pigment, when freshly applied, is absorbed by the small pores of the rock, consequently staining the rock. When the water or the organic binder evaporates it leaves the iron oxide pigment, which becomes part of the rock. The pictograph then weathers away at the same rate the rock does. Some of the remaining pictographs may be thousands of years old. Who were the American Indians of the John Day Basin? The Northern Paiutes, Umatilla, Wasco and the Warm Spring Indians are some of the tribes known to have frequented the John Day River basin in the recent past. Evidence of an American Indian influence in the basin is provided by the pictographs and discovered artifacts. Seasonally, American Indians used the John Day River basin as a means of subsistence and passage. The basin provided riparian, rangeland, and forested habitat for fishing, hunting, and gathering food. Pictographs are protected by law on all federal land… Preservation of the pictographs is vital since they represent a
