Arctic Circle level, although in mountainous regions there is often no direct view of the true horizon. Only four million people live north of the Arctic Circle due to the severe climate; nonetheless, some areas have been settled for thousands of years by indigenous peoples, who today make up 10% of the region's population. Tens of thousands of years ago, waves of people migrated from eastern Siberia across the Bering Strait into North America to settle. The largest communities north of the Arctic Circle are situated in Russia, Norway and Sweden: Murmansk (population 307,257), Norilsk (175,365), Tromsø (71,295), Vorkuta (59,231) and Kiruna
The Arctic Challenge and has been integrated into the TTR World Snowboard Tour at the 5Star level. Oslo is south of the Arctic Circle, and is thus not in the arctic. Due to its great success last season it has moved to the TTR 6Star level, the highest status an event can hold on the World Tour, giving out 1000 TTR ranking points to the winner and $100,000 in total prize money. It is now the only 6Star rated event owned by a professional rider. At the Arctic Challenge 2007, the organizer and snowboard legend, Terje Håkonsen broke the highest air record in