John, I guess I missed something about the bridge being elevated. Obviously, you can't do that with a dual track bridge, so I just assumed the grade down to the bridge hadn't been finished and the elevated yard was a leftover from an experiment. I don't think it's practical to raise the yard, but then I'm not sure where you were going with that, so it's hard to comment further.
Since you seem to want different elevations around the layout, check out this version. I changed the base elevation to 1" so I could go down a bit with the part of the orange line that's covered and lower the grade a bit along the top down to the bridge. So, the yard and some other tracks are at 1" and the rest are as indicated. I also fiddled some more with the yard trying to make it somewhat functional using your 4-way switch. However, the yard being separated from the turntable and engines having to travel through the double crossover is far from ideal. Mind you, it can work, but you'll have to stop trains on the mainlines to do it.
