Recreational user fees at work

Grand Canyon National Park charges a $25 per vehicle user fee.  Fees are used for infrastructure improvements to the park, and they seem to be working.  I couldn't help but think of John when I saw the sign to the right.  Sorry for the picture quality.  It's the best I could do while trying to inconspicuously take a picture of a restroom with a camera phone while people are streaming in and out (the sign in the middle reads UserFee: Your Fees at Work).   My kids hid in shame.