The Parker Bridge carries PA-368 over the Allegheny River between Armstrong and Clarion County was determined eligible under the newly developed point system for evaluating bridges for the National Register of Historic Places. This 4-span, rivet-connected Parker thru truss, was built in 1934 and receives points for being a multi-span bridge, expressing exceptional span length, and being built at a 6.32% grade which was an important achievement at the time of its construction. Photo courtesy of PennDOT.