Findings of excavations at the burial mound-vault Skalnaya 5 of the Tes stage in Khakassia are presented. The article focuses on ritual aspects of clay-plaster coatings of human crania and their semantics. The coating was applied to cervical vertebrae and trepanned skulls. It consisted of a single type of local clay; sculptural portraits were modeled of plaster (with two main layers and a finishing layer), and pigments were made of ocher with various shades, cinnabar, and charcoal. The masks, apparently made by various artisans, represented unique faces with ethnic features. Female masks had more elaborate paintings (one or several trefoils) than male ones which were uniformly red. Wooden structures, certain details of the funerary rite, and the technology of clay-plaster coatings reveal high similarity among the burial mounds at Skalnaya 5, Noviye Mochagi near Kaly, and Lisiy near Sabinka, possibly because they were contemporaneous (first to third centuries AD). Trefoil designs are paralleled by those on two female masks from Kamenka III burials, suggesting that these women belonged to a single ethnic group. Nomadic pastoralists of Southern Siberia did not make sculptural representations of painted plaster, suggesting that the tradition was introduced from the west. But conceptual resemblance is found only among Egyptian plaster funerary masks of the Roman Age.