Great, that really helps, thanks! So I could easily do that across the back portion of the run.
My biggest problem with O gauge so far, coming from HO and N gauge as a kid, is "eyes bigger than my layout" syndrome. LOL. You have no idea how many things I've bought, and then realized they don't fit anywhere. I was trying to avoid that with the trestles and thanks to your help I should be safely able to get them and use them.