[1] Variations of the marker could be found at highway crossings of creeks, rivers, trails, borough lines, and other points of interest.
[2] The Keystone Markers were products of the height of the Good Roads Movement that opened highway travel to the masses.
[3] The Keystone Markers were the signature project of the Department, the second oldest of its kind in the nation and predecessor to today's PennDOT.
Grant funding has enabled patterns to be created and the first replica Keystone Markers are slated to be installed in 2012.
[3] The co-founders of the trust are attorney and employee of the National Railway Historical Society Nathaniel Guest and historian Greg Prichard.