You'll get the list of all the counselors but I asked my kids (and paid attention to whom I saw with the group (careful, many work the desk)) and wound up giving out cards to three counselors (my twins were nine). I gave several cards each since they are now SO cheap at Sams. Just a hint, though, give them out mid day on the last day, by the evening all three were done with their shift for the eveing. I could leave (which I did) them but my kids really wanted to say thanks themselves.
I would plan three each child (you may have fewer if your child has more of a favorite).
I went with 24 cards since they were less than $3 each and bundled several into the tip envelopes. I also figured I could take home the rest and use the minutes at home if need be. I returned home with two cards.
Have a great trip
Barbara