ROW width can vary a bunch. I know of places where it only goes ditch to ditch and the state doesnt own the ditch. I will also venture to guess that the state employee thats saying go ahead and get the wood, probably doesnt have the authority to give the wood away. Just because they have a orange vest on and drive a state vehicle, doesnt mean they can give anything away.
That is why in my opinion if you are interested whether x,y,z is legal or permissible it is best to email the relevant government department or agency rather than to call or talk to them in person. First of all if the answer you get is in writing the person or government employee who wrote that answer is more likely to have done more research and made sure that its legal rather than just say what they think of off the top of their head. That is assuming they mistakenly thought they had the authority to give something away or were ignorant of the law themselves. Secondly its also better to get it in writing because the government employee maybe deliberately misleading you, and telling you that something which they know is illegal to be legal, if it is an unrecorded conversation and thus committing entrapment. They can't do that if you have their reply in writing and have it as proof if any trouble comes up.