I guess I'm trying to understand the operational flow. From what I see, you have the sawmill at the summit, with a dock and trestle bridge much lower down. Staging is below that. But there is no logging or log loading area. Seems to me that ideally you would want a loads in/empties out arrangement at the sawmill, and an empties in/loads out arrangement at the log loading area.
Don't know a lot about Eastern logging. But Western logging tried to put saw mills beside some kind of water storage for the logs where available. Typically, the best harvestable stands of trees were upslope. So logs would be loaded up in the mountains, transported downhill to the saw mill, and then further transported to some kind of interchange with another railroad, or to a marine terminal on a large lake or ocean port.
I would draw your 2nd and 3rd levels to scale, super-imposed on each other so things like clearances and grades can be checked. Also, with a non-scale drawing curves and turnouts don't take up as much room as in real life, and it's impossible to know whether passing sidings are long enough for your proposed train length.
yours in scale logging