Though Calico and many other previously inferred pre-Clovis sites may ultimately be accepted as "legitimate," the real challenge is to predict the general location and to actively explore other such sites. But where? Logically, they should occur on surfaces about 200 ka old. But such surfaces are rare owing to rapid fluvial dissection or to later covering by sediments. Indeed, most of the world's geomorphic surfaces are no older than Holocene (~10.5 ka). There are exceptions, however. For example, some remnant, high-level alluvial fans in the Mojave Desert are more than about 100 ka old, recognized by their tightly packed desert pavement, their dark- colored patina (desert varnish), and their strongly developed surface soils (relict paleosols; Shlemon, 1978). But such desert surfaces are, and were, inherently inhospitable for continued human occupance. Therefore, few high concentrations of undisturbed artifacts are likely to be found.
In contrast, the most promising, unequivocal Early Man targets are buried, often under many meters of sediments. Only a fraction of the ancient surfaces (buried paleosols) are ever seen, usually in fortuitous road or mining cuts. The most favorable Early Man targets are old shorelines that mark the junction of diverse environments, and thus are particularly susceptible to artifact concentration and preservation (Budinger, 1992).
Though rare, such paleo-environments may also be exposed in natural cuts. Ironically, one of the best Early Man "targets" are natural exposures that occur very near the Calico site. Indeed, the full acceptance of Calico may not come from collecting more on-site artifacts, but from systematic observation and possible excavations in the nearby Manix Lake beds (Shlemon and Budinger, 1990). The stratigraphy of the well exposed Manix beds is remarkable, for these beds range in age from about 20 ka to 290 ka, recording climatic and sedimentation change in this part of California for much of middle and late Quaternary time; they interfinger distal fan sediments that emanated from the Calico Mountains and other nearby "quarry sites;" they bear several datable ash beds, one of which is an estimated 185 ka, tantalizing close to the 200 ka age for the Calico artifact-bearing beds; and they contain abundant vertebrate fossils. In sum, the Manix Lake beds are a classic Early Man target. They may indeed be the place for a new breed of archaeologists and their geoscience colleagues to explore unabashedly for pre-Clovis sites. Such endeavors are no longer far fetched, particularly in light of the recent Monte Verde and Diring discoveries. Accordingly, it appears that we will soon see a "quiet revolution" in New World archaeology whereby mainstream archaeologists reinterpret their data and thus "document" pre-Clovis sites. If so, New World archaeology will take a giant step forward, perhaps analogous to the now-famous 1970's "plate tectonic revolution" in geology.
What has to be borne in mind is that the "people" of pre-history are not the same species as those making history here during the last 6,000 years, or so. No respectable anthropologist I am aware of asserts anymore that these older species are us. "Something" unique happened about 6K years ago, perhaps using the same basic bodies as before, but we clearly ain't the same as them.