After giving the layout a name and a setting, I started doing more research into the area I'm modeling so I can get a better idea of the terrain, and also pick up on features of the real railroad that have counterparts on the layout, so that I could name them. In particular, I was interested in finding bridges similar to those on the layout.
It didn't take long to find a perfect candidate for the foreground trestle. Just south of White Haven, the Reading and Northern—following the Lehigh Valley ROW—crosses over the roadbed of the long-abandoned CNJ, and then the Lehigh River; indeed, the two lines and the river all intertwine as they pass though the scenic Lehigh Gorge. They also frequently make sharp twists and turns, sometimes doubling back on themselves, so the layout's loops would not be all that far from reality.
After exploring the area with Live Search (perhaps one of the most useful railroad research tools ever), I decided the first bridge south of White Haven would do nicely; I'd simply have to pretend that, for the purposes of the layout, the CNJ ROW was still in use. That first bridge is really interesting: it appears to be a deck plate girder bridge that was once double-track and since converted to single-track. The aerial photos of it very nearly convinced me to model it as-is, instead of the through plate girder I'd planned.
For the other river crossing I'd wanted to build a stone arch bridge. Sniffing around, I found a little one just south of Lehigh Tannery. Although it was considerably smaller than what I needed, it would have to do. Many miles to the west, near a town called Dippel Manor, I found something much closer to what I'd wanted to build.
The bigger discovery was Lehigh Tannery itself; it was much closer to the kind of town-ish scene I'd wanted to model than White Haven, which was far too urban for my purposes. But Lehigh Tannery wasn't perfect either; it would have to aquire a fictional station.
The tunnel was a toss-up; there are a few along the line. I was initially drawn into the area by White Haven Tunnel, which is just north of town, burrowing under unremarkable countryside. Much closer to the visual quality of the layout's tunnel is Rockport Tunnel, which is several miles south of White Haven; it's a "shortcut" past a sharp bend in the river known as Switch Tail Curve, which the CNJ followed. The whole area is spectacularly scenic, and while I hadn't planned on modeling any truly "spectacular" scenery, the Rockport area is irresistible.
Shifting the entire layout's setting south to Rockport would be a break from the initial concept, but it would also offer an opportunity for a more cohesive set of features. However, Rockport isn't so much a town as a locale, dominated by farmland. I'd wanted to model a small bit of town-like area, so I'd have to do a massive amount of selective compression to pull Lehigh Tannery into the scene. But I didn't care much for the name Lehigh Tannery for the town; I preferred the rustic-sounding Mud Run, which according to the map is located on a mountain ridge near Rockport, where a road dead-ends under a high-tension line; population zero.
So, do I rename the layout? Ultimately, "artistic license" won out over the nascent prototype modeler in me, and I decided the layout will remain White Haven Junction, with the trestle being the Lehigh Valley crossing the CNJ south of town. But now the tunnel will be Rockport Tunnel, and the snippet of town shall be Mud Run. And it was good.