News of the discovery spread slowly, but some miners arrived in the summer of 1909 and built a small camp they called Flat City.

[3] Beaton, Peter Miscovich, Lars Ostnes, and David Strandberg were prominent early arrivals who mined successfully long after the initial boomtown faded.

By 1914, the community had grown to about 6,000 people, complete with an elementary school, a telephone system, two stores, a hotel, restaurant, pool hall, laundry and jail.

On July 20, en route to Fairbanks from a stop in Khabarovsk, Siberia, Post nosed over his high-wing, single-engine Lockheed Vega, the Winnie Mae, in Flat.

A replacement propeller was brought to Flat by pioneer Alaska flier Joe Crosson and the airplane was repaired by John Miscovich.

According to the United States Census Bureau, the CDP has a total area of 161.1 square miles (417 km2), all of which of is land and none of it is covered by water.

It did not appear again until 2000 when it was made a census designated place (CDP) with its boundaries including the former city of Iditarod and the former mining village of Otter.