I fixed everything I could. I don't know who created the page, but they were the ones who went with the Conrail bridge location. They definitely mislead me, and historical aerials didn't help me either as the span was removed before aerial pictures were taken for their website and their topographical maps didn't list the HBT line whatsoever. I thank you for clearing this up via the aerial picture from the PA Turnpike archives.
That's one of the things I'm trying to get through to you, this was never a PC span. It was H&BTM RR only.
Now, although there just a few remains of both bridges left, they are the northern abutment of the Thropp, and the southern abutment of the MT. Dallas. The northern abutment of the MT. Dallas was completely removed. A part of the fill and southern abutment of the Thropp may still be visible from the westbound lanes of the Turnpike in non-foliage seasons.
I got my bridge its own page and moved the pen on this one up. I think we can change some more information, as it looks like the Pennsylvania or its successors never used this span.
C. 1940 aerial photo from PA Turnpike Archives
Bottom bridge is MT. Dallas Pennsylvania RR bridge, later Penn Central, and then Conrail.
Originally built 1871, modified 1938 and 1947 for US30 expansion.
Middle bridge is Thropp Viaduct, built early 1900s for Huntingdon & Broad Top Mountain RR to access Thropp Iron Works on south side of river. Ironworks bankrupt in 1924, little use afterward until PA Turnpike construction severed the spur line. Apparently dismantled by 1950.
Oh OK. I think my additions were for the actual bridge at Mount Dallas and the postcard is for the other location just east of here.
And also, it looks like the author of the article got mixed up, as I can't anything for the Mount Dallas siding going east of Everett, as it looks like the track remained west of Everett and continued going north to some quarry.
These 2 bridges are in different locations, were owned by 2 different RRs, and were built decades apart.
OK. I wonder if one of these is a successor to the other one and could have its own page created. I don't know which one would go where though, and it was unintentional as I followed the pin that the previous author used.
The sign in the 5th picture though is present on Google Street View.
There are two different bridges in this post.
If you go further east(?) on Google Street View on US 30, I found what looks like an old bridge pier around the coordinates at 40.010873,-78.387952. I can't find anything that crossed there looking at historical aerials as far as back as 1962 and topographical maps show nothing. Just seems mysterious to see this massive monolith overlooking a major highway. https://goo.gl/maps/Jg2rnq4MdUV23mbv5
And you should add the pictures of the removing piers for the spans if you have them, as they will become lost to mother nature eventually if the state or commonwealth doesn't decide to order their destruction.