Riverdale was laid out in 1890 when the Kearney and Black Hills Railway was extended to that point.

[5][6] According to the United States Census Bureau, the village has a total area of 0.26 square miles (0.67 km2), all land.

There were 88 housing units at an average density of 338.5 per square mile (130.7/km2).

19.2% of all households were made up of individuals, and 13.7% had someone living alone who was 65 years of age or older.

19.3% of all households were made up of individuals, and 7.2% had someone living alone who was 65 years of age or older.

About 3.8% of families and 7.8% of the population were below the poverty line, including 17.9% of those under the age of eighteen and none of those 65 or over.