Profile drawings showing the layers documented at the Rush site. The bison camp is Occupation 4, which is represented by Feature 5. The radiocarbon assays shown here (such as 360 +/- 84, a radiocarbon-year age estimate) include several that seem too old to make sense; during analysis researchers look at the overall patterns and reject the aberrant assays. (There are many reasons that affect the accuracy of radiocarbon age estimates, which is why multiple assays are needed to evaluate the age of a site deposit.) Adapted from Quigg and Peck 1995, Figure 5.4.