North of Tunkhannock (Nicholson) Viaduct on Route 11 there is its little brother, the Martins Creek Viaduct, between Hop Bottom and Kingsley.
Less dramatic height-wise is the former
Pennsylvania RR bridge over the Susquehanna above Harrisburg at Rockville. (That was featured on several poster-sized PRR calendars back in the day.)
There is another
DL&W viaduct over the Delaware River at Slateford, between Portland and the Delaware Water Gap. That one
I've been to within the last decade.
I'm sure there are many more, although for being impressive, the Tunkhannock I believe was and still is the largest reinforced concrete railroad structure in the world. The DL&W was heavily into that in the early 1900s.
There are some major structures out in the Pittsburgh area too.
BridgeHunter.com and
HistoricBridges.org are two sites that might be worth some research.
(My aging brain may come up with more if it works at it long enough.) At least one other I remember was scrapped quite a few years ago.