First I will post my question. I think it might be easier if I do this.

Now I figure that the counsellor can take two of the four paths to determine if the campsite is down either of them. However, he still must depend on the campers to find out whether the remaining two paths lead to the campsite should the counsellor not find the campsite him/herself.

Now given that three of the campers lie, and there are two remaining paths, how many campers would the counsellor need to determine the proper path to take should the campsite not be down the paths the counsellor takes.

I would think that if the counsellor sent seven campers (three of which could lie) down one path one trip and the same seven campers again down the other path, then the counsellor could take the majority decision and determine what path to take.

Is there any way that I can optimize this answer? That is, is there any way that I can use less campers than seven?

I can't think of any other way given three campers that lie.