In certain very scenic parts of the United States, sightseeing flights are an important part of the tourist industry. An air tour operator is an individual or company that flies sightseeing trips on at least a part-time basis. In the United States, the air-tour business is concentrated mainly in Alaska, particularly around Denali National Park, and the Grand Canyon and at two locations in Hawaii: Haleakala National Park on Maui and Hawaii Volcanoes National Park on the Island of Hawaii. While the Grand Canyon and Alaska operations include about a 50-50 mix of fixed-wing aircraft and helicopters, air tours in Hawaii are almost exclusively done by helicopter.