This paper contains the results of a study of human remains—artifacts, workshops, camp sites, and hearths—and of the associated animals found in the Berclair terrace deposits of the Mission River drainage system of the Coastal Plain region of Texas. The artifacts are referable to Folsom, Yuma, and cultures known from central Texas, and some are not definitely placed as to cultural position. The Folsom and Yuma cultures are found near the base of the deposit; the central Texas culture occurs in the upper part but may likewise extend to the lower levels. The extinct mammals of the formation include mammoth, mastodon, horse, bison, camel, dire wolf, peccary, armadillo, glyptodon, and ground sloth. There are also some extinct turtles of which the species have not been determined.
Since deposition of the terrace, regional uplift has rejuvenated the streams which have now become intrenched in the Berclair terrace deposits. Due to this uplift the present streams have a steeper gradient than the earlier streams. On stratigraphic evidence the Berclair terrace deposits are shown to be the upstream equivalent of the Beaumont formation, probably of Lower Beaumont age. The correlation, as indicated by the vertebrate fossils, is with the Melbourne formation of Florida and almost, if not exactly, with the Tedford bone bed of San Patricio County, Texas. The paleontologic and stratigraphic evidence indicates that the formation and the included artifacts and fossils are Pleistocene.
The fact that man inhabited these valleys during the Pleistocene implies, consistent with other evidence, that he had then attained a wide distribution on the continent. The varied and specialized cultural development of the Mission River valley inhabitants suggests that this occurrence does not represent the earliest occurrence of man in North America. The time of arrival of man on the continent is yet to be determined.