Results of radiocarbon dating of items from mound No. 51 of Ust-Tartasskiye Kurgany burial ground are presented. This is a key site of the Sargat culture in Baraba. Characteristics of samples and pretreatment procedure are provided. Twenty-four radiocarbon dates were generated. Radiocarbon ages correlate with biological ages of the deceased persons. Bayesian KDE chronology modeling suggests a short-term intense use of the site for burying those who died between the 3rd and 1st centuries BC. Based on MCMC-modeling, a conclusion is reached about two periods in the use of the space allotted for graves between 200–40 BC. Burials of the “first period” (~25 %) could have been repeatedly made before 150 BC. Most burials (~75 %) were likely arranged between 150–120 BC. The last burial in the mound (no earlier than 110 BC) is No. 13. Minor differences in 15N isotope apparently evidence various diets of males and females at the second period.