Archeological research over the past several years has started to provide evidence relevant to understanding both the timing of and processes for human colonization of the high Qinghai-Tibetan Plateau. Much of this research has been in the Qinghai Lake area and the Qaidam Basin in the northeastern Qinghai-Tibetan Plateau. However, chronological data are still limited. Recently, a hearth was discovered in the Jiangxigou site in the south of the Qinghai Lake area, which was likely used by prehistoric hunters. The site is in the mouth of a canyon approximately 4.5 km from Qinghai Lake. Previous ages in this site are based on C-14 dating only. The current study provides additional OSL dates for the hearth. The ages of four OSL samples bracketing the hearth range from 12.9 +/- 0.9 to 14.4 +/- 1.0 ka, but standard deviations overlap extensively and they likely represent the same age. The OSL ages show that by about 14.3 +/- 1.0 ka prehistoric peoples were living in the Qinghai Like area. (c) 2012 Elsevier B.V. All rights reserved.