Modern forms of transportation and communication have done much to break down the isolation of life in the North, and contemporary North American popular culture is evident in most communities. Government assistance in the development of major resources has been provided mainly in the form of roads, electric power facilities, mapping, and geologic services. Another fifth of the labour force worked in public administration. Tourism is an important portion of the service sector; adventure tours, driving tours, sportfishing, hunting, and such natural phenomena as the aurora borealis and long summer days attract visitors from other parts of Canada, Japan, and the United States. The territorial government also gives financial assistance to many students who pursue postsecondary education, either inside or outside the territories. Mackenzie River delta on the, arctic Ocean to northwestern, manitoba and is just west ofand roughly parallel tothe border with Nunavut. Although the climate of the Mackenzie Lowlands is milder than that of the remainder of the territories, it is still cool enough to limit navigation on the Mackenzie River system to about four months a year and to cause a permanently frozen subsoil, or permafrost. The Fort Smith region has most of the territories approximately 130,000 square miles (330,000 square km) of forested land, but, even there, large stands of marketable timber are not plentiful. (The vast majority of Canadian Inuit are found in Nunavut.) The remainder of the people in the territories are mainly of European descent. In 1880 the Arctic islands claimed by Britain also were placed under Canadian jurisdiction.