You might want to check with the camp director first. When I worked as a camp counselor we were not allowed to take gifts from parents, no mater what the gift was.
This was done for two reasons. First, giving gifts gives the impression that one counselor is superior than another and that you are showing favoritism. This is not good.
Second, it really isn't fair to other counselors who have worked as hard as your child's counselor. It's really a sticky situation to get into. Camp counselors are different from day care providers who spend much more time with your child. It's ok to gift these people, but it it's a touchier deal with camp counselors.
I speak from experience after having been left out one summer after being left out. It stings.
Hope I didn't offend you. Just my perspective.