Colonel Denning State Park is located within the bend, in the valley of Doubling Gap Creek, which flows south out of the mountain area and across the township to Conodoguinet Creek, which forms the southern boundary of the township and is a tributary of the Susquehanna River.

The Pennsylvania Turnpike (Interstate 76) crosses the southern end of the township, but with no direct access.

15.5% of all households were made up of individuals, and 6.3% had someone living alone who was 65 years of age or older.

In 1865, prospectors drilling for oil in Lower Mifflin Township struck a large high quality aquifer.

Later, the Cloverdale Spring Company was formed and used the water for its soft drink business.

The park is named for William Denning who lived near Newville and manufactured cannons for the Continental Army during the Revolutionary War.

Tuscarora State Forest is also administered by the Pennsylvania Department of Conservation and Natural Resources (DCNR) and was named for the Iroquois-nation tribe that once inhabited the area.