Siberia is a vast and varied region, linked horizontally to the circumpolar Arctic and vertically to Mongolia and Central Asia. Nineteenth-century anthropological fieldwork was important abroad, particularly in America. From the 1920 to 1980s, Siberia was almost totally isolated from outside research and from comparative anthropology. However, Soviet anthropologists conducted lengthy fieldwork, producing a huge corpus of valuable material in Russian. Their questions were specific to their ideological situation, for example placing indigenous peoples in a Marxist evolutionary framework, and during the 1930s, many suffered imprisonment and execution. Topics became more sociological in the 1960s, and when the region opened to foreigners around 1990, a new wave of young researchers conducted long-term fieldwork, producing a flourishing new literature in English and shifting the emphasis from historical reconstruction to current issues. Topics in this new literature include the state, agency, modernization, shamanism, animal spirits, resource development, and empowerment. Throughout all periods, indigenous people themselves have also been involved in research.