A series of radiocarbon (14C) dates of peat and other materials, containing organic matter, were obtained from Belyi Island. We have identified a large group of dates associates with MIS 1, as well as a significant group of dates associated with the Kargin (MIS 3) period (40–31 ka cal BP). A large number of dates from the Late Glacial period and from the Early Holocene (MIS 1—ca. 14–9 ka cal BP) point to this time interval being associated with warm climate conditions (the Holocene thermal maximum). The climate cooled off significantly during the Middle and Late Holocene, and the intensity of peat accumulation declined. The dates from the MIS 2 period are missing, due to the conditions of this period being extremely unfavorable for the accumulation of peat, as well as of other materials suitable for 14C dating.