Well, I got you started on this, so I'll step in. There's a lot of examples out there, but a good one is at Corry, PA. This is a crossing of the Erie-to-Williamsport PRR line (today A&E) with the Erie/EL (today WNYP) NY-Chicago main line. Get your Google Earth on, it's pretty clear. PRR comes into town from the southeast and heads northwest. EL came into town from the northeast and headed southwest, kinda. So at Corry there was and is a diamond, it was 2 EL over 1 PRR, now it is 1 on 1, but after the diamond the two railroads ran only 100' apart through Corry, sharing a station, freight station, elevated gate crossing towers, etc. Today you can see the 'crossover' between the two just west of the second crossing - that's the interchange. These two ran side by side like this for more or less 12 miles to Union City. Even today there has been active discussion of abandoning one of the two lines for reduction of duplicate lines. I don't know when I've seen two parallel competitors share so many buildings through a downtown corridor with everything in the middle: http://www.prrerie.com/corry.shtml But thats a solid example of putting everything in the middle and putting a crossover between. And for trivia buffs, the surviving building on the "S" road curve, south of both tracks and a little west of center, is the main erecting building for the Climax Locomotive Works. Still there. Now...the river canyon... two railroads....spectacular. Let me think.... Well, CN and CP fight it out like that in the Frasier River canyon, pretty spectacular: http://www.railpictures.net/viewphoto.php?id=283812&nseq=31 In the east, Lehigh Valley, CNJ, and L&NE all fought it out in the Lehigh River Valley, quite the gorge: http://historical.mytopo.com/getImage.asp?fname=mauc24sw.jpg&state=PA http://freepages.history.rootsweb.ancestry.com/~carrleith/images/aquahicola.jpg It's gone today, but the Letchworth State Park had the PRR and the Erie crossing each other beside a waterfall, no less. The high bridge is still there, the PRR Rochester line up on one side is a memory: http://www.railpictures.net/viewphoto.php?id=251519&nseq=4 Despite the vegetation you can just see the bench up on the LH side were the PRR was, it ran parallel to the river, rather high up. http://www.letchworthparkhistory.com/lpa93.html Check out the topo map, river gorge, two bridges....hmm. http://historical.mytopo.com/getImage.asp?fname=ptag05se.jpg&state=NY You're in good company.