Based on 1900-1917 archival data and 1947 topographic maps large contours of burnt land in the first half of the 20th century were identified. The total burnt area was more than 200 000 ha, which is about 10 % of the entire area of the plateau. We specially focused on Zolotitsa region, where forest fires in the 1930s covered about 130 000 ha. It is shown that the process of natural regeneration of conifers (especially spruce) in pre-tundra forests (northern taiga subzone) may take a long time of up to 150-200 years.