Flat is a census-designated place (CDP) in Yukon-Koyukuk Census Area, Alaska, United States. Prospectors John Beaton and W.A. Dikeman discovered gold on Otter Creek. News of the discovery spread slowly, but a some miners arrived in the summer and built a small camp they called Flat City. More gold was discovered on nearby Flat Creek and more miners. Beaton, Peter Miscovich, Lars Ostnes, and David Strandberg were prominent early arrivals who mined successfully long after the initial "boomtown" faded.