Darlington and South Beaver townships are connected by the Watts Mill Bridge, which is listed on the National Register of Historic Places as the "Bridge in South Beaver Township".

As of the 2000 census,[6] there were 2,974 people, 1,090 households, and 821 families residing in the township.

There were 1,139 housing units at an average density of 38.0 per square mile (14.7/km2).

21.7% of all households were made up of individuals, and 7.8% had someone living alone who was 65 years of age or older.

Portions of the Pennsylvania State Game Lands Number 285 are located in the township.