Lower limb entheseal changes are evaluated in order to reconstruct activity levels and more fully understand cultural and behavioral variation among the middle Holocene (ca. 9,000–3,000 years BP) foragers of Siberia's Cis-Baikal region. The four cemetery samples examined span a period of diachronic change characterized by an 800- to 1,000-year discontinuity in the use of formal cemeteries in the region. Two of the cemetery samples represent the early Neolithic Kitoi culture, dating from 8,000 to 7,000/6800 cal. BP; the other two represent the late Neolithic-early Bronze Age Isakovo-Serovo-Glazkovo (ISG) cultural complex, dating from 6,000/5,800 to 4,000 cal. BP. Findings suggest a dynamic pattern of cultural variability in the Cis-Baikal, with spatial distribution (i.e., site location within particular microregions) appearing to be just as important a factor as cultural/temporal affiliation in explaining intersample differences in entheseal morphology. In addition, intrasample comparisons reveal increasing sexual disparity with advancing age at death, emphasizing the influence of sex-related activities on lower limb entheseal changes. Finally, results from the separate fibrous and fibrocartilaginous datasets appear to be largely congruous, implying that activity patterns in the Cis-Baikal may have similar effects on the morphology of both types of entheses. Am J Phys Anthropol, 2013. © 2013 Wiley Periodicals, Inc.