Casselman River Bridge State Park 
10240 National Pike
Grantsville, MD 21536
301-895-5453
http://dnr.maryland.gov/publiclands/Pages/western/casselman.aspx
State Park: Fish, History, Picnic, Walk
Originally constructed in 1813-14, the fine single arch stone bridge once served the old National Road which linked Cumberland, Maryland with the Ohio River. Several picnic tables are available on a first-come, first-served basis. The Casselman River is a popular spot for fly-fishing.