This article presents the results of radiocarbon dating and a chronology of the Preobrazhenka 6 site of the Odino culture (Baraba forest steppe, western Siberia). Currently available 14C data for the necropolis do not allow accurate determination of the presence or absence of reservoir effects, and as such, further research is needed. Accelerator mass spectrometry (AMS)14C dating of paired samples of terrestrial faunal and fish remains from a Neolithic pit suggest the absence of a reservoir effect in fish bone collagen. Middle Bronze Age burials have therefore been estimated to date to the 23rd–20th centuries cal BC. Pits with fish remains are dated earlier than burials, to the 63rd–61st centuries cal BC. Stable isotope measurements of human bone collagen (high δ15N and low δ13C values) indicate diets based on С3 plants and fish. Apparently, the role of animal protein in the diet was not significant. Dental paleopathology analysis has confirmed the important role of wild plants in human diet. Neolithic fish bones are elevated in δ13С [–13.5‰, average mean (n = 4)]. They are significantly different from the associated values of fish from the Late Bronze Age settlement of Chicha 1 [–22.5‰, average mean (n = 10)], which is also located in the Baraba forest steppe. The difference in δ13C values in fish bones may be determined by the origin of the samples, being derived either from lakes or rivers.