[2] The United States Penitentiary, Lewisburg is located in Kelly Township, and not in the nearby Borough of Lewisburg, whose post office serves most of the township (except for its northeastern corner, which is served by the West Milton post office).

The Slifer House was added to the National Register of Historic Places in 1975.

[3] According to the United States Census Bureau, the township has a total area of 17.1 square miles (44 km2), all land.

As of the census[5] of 2000, there were 4,502 people, 1,313 households, and 778 families residing in the township.

37.3% of all households were made up of individuals, and 23.3% had someone living alone who was 65 years of age or older.