I know lots of people that take their boats up the lake and park at the dock there and then ride mountain bikes, dirtbiikes or quads up to do some fishing. I havent been fortunate to get up there yet though
which is weird because i grew up in Pitt
I have been told that from the dock your looking at about 17-20km's before you hit the good fishing water.
If your going to take a boat up there i suggest something on the slightly larger size like a 16 footer or better. The lake is notorious for getting very windy in the afternoon and a 12cartopper can be very dangerous to be in and you dont want to be getting stranded out there.
When it comes to the logging roads. If im correct they are gated and locked and you cant pass without permission or a key. I could be wrong though but i have been told by people that go up there yearly (lots of trips yearly) that there is no way in hell you can drive up there. So im assuming that only the lodge gets passed those gates for supplies and stuff. There are some guiding outifts that have trucks already stationed up there so they can drive the roads after boating the lake.
Try giving the lodge a call and see what type of information they can give you. They might however try to convince you to stay at the lodge
which i would love to do when i can afford it because drifting the river and fishing is better then anything.