This Sunday (May 20), they are visiting the Smith Trusses and Iron Furnaces in Southern Ohio.
Start point is Peebles, Ohio, at 10 AM. Bring your own picnic lunch.
More details can be found at http://oldohiobridges.com/ohba/index.htm (http://oldohiobridges.com/ohba/index.htm)
(This has nothing to do with the Dayton Roadmeet in June)