AU, yes I'll have to practice my picture posting. There were two steel structure bridges south of Blackwell.

As for the GAP, any area from Connelsville to Cumberland Maryland is pretty nice. I especially like the section from Confluence to Rockwood. It snakes along the Casselman river which is very nice. Just north of Meyersdale is the Viaduct which is a span built in the early 1900's. Its a little over 1900 feet long, and 100 feet high. Then south of that, past Meyersdale is the continental divide and just before the Mason Dixon Line is the Savage tunnel, and a great overlook. From there on to Cumberland is all down hill, and a very nice easy ride. Its a pretty good grade, and would be a heck of a workout to pedal that from Cumberland to the divide.

Not sure which part of Pa you are from, but another trail I really liked was the Allegheny river trail which runs from Emlenton just north of I-80 to Franklin, and is mostly all asphalt. It includes two tunnels you need a light for. The Rockland and Kennerdale tunnels. The whole trail is 26 miles long, but a nice ride is just through the Kennerdale tunnel and back to Emlenton. Which would be around 30 miles round trip.