Colonel Denning State Park, in north central Cumberland County, is in Doubling Gap, so named by the ?S? turn where Blue Mountain doubles back on itself. This feature may be seen from the Doubling Gap Vista in adjacent Tuscarora State Forest. The park has 273 acres of woodland and a 3.5-acre lake.

William Denning, (1737-1830) American Revolution veteran for whom the park is named, was never a colonel but he is deserving of a place in history for his manufacturing of wrought iron cannons. William Denning served his country as a sergeant from March 1778 to April 1780 in Nathaniel Irish?s Company of Artillery Artificers in Benjamin Flower?s Regiment. Denning was stationed just outside of Carlisle, PA at Washingtonburg Forge, now Carlisle Barracks. The forge provided armaments for the Continental Army, including cannons. It is at this forge that William Denning made wrought iron cannons in a process of welding gads (strips) of wrought iron in successive layers to produce a cannon lighter and better able to resist failure during firing than cast iron cannons.

Unfortunately, none of Denning?s cannons survive today. Historical documents help us imagine from what Denning?s cannons looked like. It is also not known when or who added the ?colonel? to Sergeant William Denning?s name. After the Revolution, William Denning lived out his life near Newville, PA and is interred with his only son and daughter in the Big Spring Presbyterian Church in Newville. His monument reads ?Blacksmith and Forger of Wrought Iron Cannon.?

The park became a state recreational area about 1930, under the Pennsylvania Bureau of Forestry, and was developed formally in 1936 through the efforts of the Civilian Conservation Corps (CCC) Camp S-111 in Perry County.

An environmental interpretor offers ecological and historical walks and programs, audiovisual programs, campfires, environmental education activities and youth programs during the summer season. A visitor center, exhibiting plants, animals and minerals found in the park, is open during the summer season.

Camping: rustic sites

The 52-site, tent and trailer campground is open from the opening day of trout season to the day after deer season in December. Each site has a picnic table and fire ring, and are near non-flush toilets and a sanitary dump station.