Hanging Rock, also known as Overhanging Rock, or locally as Drummond's head, is a historic natural feature which is located in Gulph Mills, Upper Merion Township,

Montgomery County, Pennsylvania Montgomery County, colloquially referred to as Montco, is a county in the Commonwealth of Pennsylvania. As of the 2020 census, the population of the county was 856,553, making it the third-most populous county in Pennsylvania after Philadel ...

. It is a large natural outcropping of

phyllite Phyllite ( ) is a type of foliation (geology), foliated metamorphic rock formed from slate that is further metamorphosed so that very fine grained white mica achieves a preferred orientation.Stephen Marshak ''Essentials of Geology'', 3rd ed. I ...

that protrudes approximately eight feet over a roadway,

Pennsylvania Route 320 Pennsylvania Route 320 (PA 320) is a north–south state highway in southeastern Pennsylvania. The southern terminus of the long route is at U.S. Route 13 in Pennsylvania, U.S. Route 13 (US 13)/Pennsylvania Route 291, PA 291 in Chester, Pen ...

(South Gulph Road), which was laid out as a public highway between 1711 and 1712. It was listed on the

National Register of Historic Places The National Register of Historic Places (NRHP) is the Federal government of the United States, United States federal government's official United States National Register of Historic Places listings, list of sites, buildings, structures, Hist ...

in 1997.

History and geographical features

The road near Hanging Rock,

(South Gulph Road), was built between 1711 and 1712 to serve as a public highway. It was subsequently used by General

George Washington George Washington (, 1799) was a Founding Fathers of the United States, Founding Father and the first president of the United States, serving from 1789 to 1797. As commander of the Continental Army, Washington led Patriot (American Revoluti ...

and the Continental Army to move troops into

Valley Forge Valley Forge was the winter encampment of the Continental Army, under the command of George Washington, during the American Revolutionary War. The Valley Forge encampment lasted six months, from December 19, 1777, to June 19, 1778. It was the t ...

for the winter encampment of 1777–1778. ''Note:'' This includes The rock formation was dedicated as a memorial to that march by the Valley Forge Historical Society in 1924. ''Note:'' This includes In 1917 and 1954, holes were drilled into Hanging Rock for the placement of dynamite in an effort to remove the rock. This, along with erosion and vehicle collisions, has changed the shape of the rock over time. The "overhang" of the rock has decreased since the invention of the automobile as car crashes have chipped away at the rock over the years. In January 2020, PennDot started a project to realign Route 320 (South Gulph Road) away from Hanging Rock, which had protruded into the roadway, resulting in limited sight distances; the project was completed in June 2022. Hanging Rock was listed on the

in 1997.

Gallery

File:Gulph Rock.JPG, Hanging Rock, c. 1919 File:Gulph rock 2019.jpg, Hanging Rock, c. 2019

References

{{National Register of Historic Places in Pennsylvania National Register of Historic Places in Pennsylvania Geography of Montgomery County, Pennsylvania National Register of Historic Places in Montgomery County, Pennsylvania Natural features on the National Register of Historic Places Upper Merion Township, Pennsylvania