- COORDINATES: 39.7969041, -76.7348531 (Believed approximate to where marker may have been.)
- COUNTY: York
- EXPLANATION OF NAME: Originally 'Rocks In Glen' (This info comes from the marker's inclusion in a 1970 booklet by Clair Clawser.)
- FOUNDED: 1838
- MANUFACTURER: Undetermined
- STATUS: Believed to be long gone. Known only from Clair Clawser book. A replica marker was found on wall of borough building by G. Smith, Feb. 2016..
Feb. 2016 photo by G. Smith
Photo of town Mural that includes the now long gone Keystone Marker
Original site likely on PA Route 216