Source: Railway Preservation News
I found the picture below taken in May 1968, not too long before all of the engines were sent to Strasburg. This is the kind of authentic setting I like to see locomotives displayed in. Roundhouse and coal dock were destroyed about 1986 or so, sadly.
Demolition of the roundhouse happened in the spring and summer of 1987.
There was some serious lobbying to get the Railroad Museum of Pennsylvania established in part at this very roundhouse, for many of the reasons: still-extant water tanks and coaling tower, auxiliary buildings, etc. There was also some minor quizzical thoughts about the feasibility of relocating Steamtown to the site at one point in the "we've got to get out of Vermont" phase; I'm reasonably certain Pennsy fanatic Don Ball was quite aware of the possibilities of the Northumberland site during his tenure as director. Unfortunately, here's the brutal reality:
1) the roundhouse, and the yard by which it was surrounded, were in a flood plain--one that takes a bit of doing to flood, but it is there. I believe I've seen photos of the turntable pit being pumped out post-flooding.
2) The roundhouse, at the time (and the site still to this day) was surrounded by active railroad trackage and yards. The nearest road access is via approximately 1.5 miles or more of private road through a railroad yard. (If I remember correctly, I had to cross one main line, six main yard tracks, and two or three sidings to get to the roundhouse, *after* PC and Conrail had made major reductions in trackage.) If this museum had been opened here in the 1970s, it would have mandated its own access road and overpasses, infrastructure costs that might have dwarfed even those of restoring a decrepit roundhouse or those of the Steamtown NHS. And for what? You still don't have a track on which to operate. (Employees actually made short-cut use of "the Rat Hole", a long underground sidewalk constructed as a bridge spanning the water of a wide underground culvert system, with access stairs poking up at the east end beside a street in a neighbourhood where many of them lived, various points in the yard, and at the yard office and roundhouse.)
3) Northumberland itself was, and still is, very badly situated for auto traffic and tourist demands. At the present time there is planning underway to construct a major four-lane limited-access highway to the west to bypass, among other places, Northumberland, Sunbury, and Shamokin Dam, theoretically bridging the Susquehanna just to the north of Northumberland Yard. The reason, among others: Traffic through Northumberland is horribly jammed from a combination of local and through traffic on two-lane streets.