I know that a lot of the wooden trestles in the area of the Tillamook Burns in NW Oregon (three separate fires) were destroyed or partially so. I remember as a boy driving to the Pacific coast from Portland, Oregon, the remains were quite visible since the last fire left miles of forest destroyed. After the fires did so much damage, logging was resumed by trucks rather than try to rebuild miles of RR lines and trestles, some of which were pretty impressive. The last time I drove down the Wilson River hwy to the coast, was about ten years ago and I could not see a single remnant, probably due to time and the extensive timber growth everywhere.