This dental study addresses the origin of the Bolshaya Rechka people in the Novosibirsk region of the Ob, with reference to the migration of Saka and Sarmatian tribes from the southwest. I compare dental features of southern Kamen and northern Bolshaya Rechka populations inhabiting the entire Upper Ob area. Dental samples from eleven Bolshaya Rechka cemeteries were studied. Findings indicate heterogeneity. Nearly all samples evidence admixture between eastern and western groups. That from Bystrovka-3 takes a separate position, revealing more eastern traits along with those marking the Southern Siberian Upper Paleolithic complex. The results enable us to evaluate the role of Saka and Sarmatian migrants from Kazakhstan, Cis-Urals, and Tian Shan. This role appears to have been relatively minor and likely indirect, upholding the ideas advanced by archaeologists. Bolshaya Rechka and Kamen populations (the latter culture was thought to include the former) are biologically distinct. Bolshaya Rechka displays continuity with local Early Bronze Age groups. The main component of the Kamen population of forest-steppe Altai, on the other hand, was introduced by Saka and Sarmatian immigrants, who, evidently, had not reached the Novosibirsk region of the Ob. Rather than moving on northwards along the Ob from the forest-steppe Altai, they turned west, toward the Tobol-Irtysh watershed.