re: Engineers of the OB: Will this bridge support a loaded log truck?

I'd say get with the contractor who's going to be clearing the land, and ask them. Granted many of the drivers are privately contracted( own their own truck and trailer), but I don't know how many would drive across that loaded.

It kinda depends on where the sets, and landings are. Last time they cleared ours the contractor brought in huge culvert pipes, laid dirt on top of them, then gravel, and used it until finished then removed it all.

If there is enough marketable timber they will find a way to get in there usually.