The Wood River Valley in Blaine County, Idaho, ties its economy to tourism more than the farming of the wider Magic Valley. It has four cities: Ketchum, Sun Valley, Hailey and Bellevue. Sun Valley Resort sits at the north end, with Bald Mountain rising beside Ketchum and the gentler Dollar Mountain beside Sun Valley. Ketchum had 3,551 residents at the 2020 census, and 48.1% of its housing units were vacant. Sun Valley, a resort town of 1,783, had 66.6% of its housing units vacant. The Union Pacific Railroad developed the resort in 1936, and the area has been a seasonal home to the rich and famous since Ernest Hemingway drew attention to it. Hailey, the county seat, had 9,161 residents and only 7.6% vacant units, and its Friedman Memorial Airport serves the resort area. Blaine County had 24,272 residents in 2020. Its cost of living is higher than surrounding areas, with a median owner occupied home value more than double the state average, and an estimated 2,540 people commute in from outside the county to work.