[5][6] According to the United States Census Bureau, the town has a total area of 0.3 square miles (0.78 km2), all land.

Fallis was founded in 1892, just south of an Indian village on the western edge of the Iowa Reservation,[6] in a wooded area and "on a long red hill.

"[7] Originally known as Mission, it was renamed in 1894 for its prime developer and first postmaster, Judge William Henry Fallis.

Although the town is mostly abandoned today, and is nearly a ghost town, during the early 1900s Fallis was a whistle-stop for several railroad lines, and was a thriving little community with stores, hotels, banks, lumber yards, and other businesses, as well as a city hall.

[6][7] After the Great Depression, the Dust Bowl, and the decline of the railroad, by 1950 the population had fallen to just 105 residents,[6] and much of the town was destroyed by fire in 1960.