Which comes first, the bridge or the gorge the bridge will span? If I build a trestle bridge first I have excavate a gorge to fit. If I excavate a gorge, I have to cut and fit the bridge into it. So, what I was thinking is that if I were to make a template for the gorge I will excavated in the styro at the edge of the layout, I could use that same template to design and build the bridge! That way the bents should all fit and I can scenic the gorge without worrying about damage to the bridge-which will stay safe on the workbench?? Any holes in that?