Fort Yukon is a city in the Yukon-Koyukuk Census Area in the U.S. state of Alaska, straddling the Arctic Circle. The population, predominantly G…Fort Yukon is a city in the Yukon-Koyukuk Census Area in the U.S. state of Alaska, straddling the Arctic Circle. The population, predominantly Gwich'in Alaska Natives, was 428 at the 2020 census, down from 595 in 2000.