Just outside the town of Grantsville, Md. is Casselman River Bridge State Park, a small, four-acre site that preserves a stone bridge that served as the original crossing of the National Road over the Casselman River. The 80-foot bridge was built in 1813, and underwent a significant restoration in the 1970s. At the time of its construction, it was the longest single-span stone arch bridge in the country.
Interestingly, this crossing was in use as part of the National Road until 1933, when the modern bridge that carries ALT-U.S. 40 was built. And in the 1980s, Interstate 68 was completed slightly farther upstream. In lobby of the Penn Alps restaurant, which lies just beyond the eastern end of the old bridge, there is an aerial shot of all three bridges crossing the Casselman River, which to me is an interesting juxtaposition of transportation history in the U.S. In fact, even from ground level, it’s possible to get photos of all three bridges together.
The park is free, but unstaffed, and is located at 10240 National Pike, Grantsville. A recently-completed walking path and crosswalk enables visitors to walk to the park and Penn Alps from Grantsville. There are picnic tables and plenty of room to walk around and fishing is allowed in the Casselman River. For more information, visit the Maryland DNR’s web page for the park here.