Here's the bridge project I was talking about.
https://steamcommunity.com/sharedfiles/filedetails/?id=2669784976

As you can see, it's a significantly smaller gap and not very high off the ground. Many of the floor boards of the bridge (that you actually walk on) are blue, but as you can see with just a tiny bit of extra height, the pieces are red.

https://steamcommunity.com/sharedfiles/filedetails/?id=2669785074

Could very well be something I'm doing wrong or advanced tactics I'm not aware of. I still don't have all the metals discovered yet, and iron gate pieces weren't around when I built this, but I think that's still going to be much too big a gap to close with a bridge of consistent height. You may need to add a contour to it like I did so it stays relatively the same height for the whole length.