40.180512, -79.131614 (approximate original location)
Large Post-mounted keystone
This sign, near the Westmoreland/Somerset County lines, marked one of the many high points along the Lincoln Highway (US Route 30). Sadly all of these have disappeared and such locations are now marked by a simpler less-iconic marker.
Photo from an old postcard provided by Dan Graham
Lincoln Highway (U.S. Route 30)