Don't forget, if you have a 4th graders (either entering 4th grade or leaving 4th grade) you can get a free federal parks, lands and waters pass. This pass lets you in national parks for free, and the BWCA for free. The last time I had a 4th grader I just gave them our pass and they refunded our entire BWCA fee. It includes all the kids in the family and up to 3 adults.
Here is the link