R. Merriam W.M. Childers R. Protsch J. L. Bischoff 1976 <div id="Abs1-section" class="c-article-section"><div id="Abs1-content" class="c-article-section__content"><p>MUCH evidence suggests that man was present in the Western Hemisphere before 12,000 yr ago, but the case has remained less than conclusive¹. In some situations, the geological age of the site is reasonably well established but the association or nature of the artefacts is questionable^2,3. In other cases, museum specimens of human bones dated by radiocarbon analysis of collagen lack desirable information concerning site location, geology, and stratigraphy even though the accuracy of their absolute ages seems valid^4–6. We report here the results of radiometric dates of the Yuha burial site from Imperial County, California, for which the geology and stratigraphy have been documented and reported in detail.</p></div></div> application/pdf 10.1038/261128a0 en Nature Antiquity of man in America indicated by radiometric dates on the Yuha burial site article