I was wondering about the same question, just from a personal edification point of view. I only spent one season working taxes in a strip mall, but i like dragonpilot's much more learned response. Just keep records in a folder in case there are any questions, and list the buck or two of interest earned on your own Sch. B if you need to submit this schedule.
People get scared of a letter from the IRS, when there isn't a need to be in most instances. Though there are times to be scared, such as intentionally hiding for-profit-business income or not pulling required distributions out after 70 and 1/2, among others. The tax filing system, as implemented, is a massive collection of errors (just ask dragonpilot about errors his coworkers have made
The IRS just sends letters out per their rules to try to get more revenue. Should a letter be received, send a letter back to them with dragonpilot's response, checking the letter with someone first though. The only really, really wrong thing you could do is to ignore their letter and hope it goes away, it won't.
If the IRS, or some bozo state tax authority, for some unbeknownst reason, says no go on that, i like Savannah's response as to "Social Club". I totally forgot about that in our training, it was only one quick mention, but it's a beautiful solution. Better than having to declare your camp as a "hobby", i.e., a business that doesn't make money, and having to pay taxes on like the first 2% of your AGI before you can deduct camp expenses, probably resulting a few hundred in unnecessary extra taxes to be paid.
Big camps usually include or know someone who's an accountant, so they can handle their own stuff easily.
As usual, with any question about or issue that involves anything relating to laws or so forth on eplaya, please ignore any guesses at what the correct answer may be, including my guess here. Most of these guesses are usually totally clueless and incredibly wrong, reflecting the respondent's preconceived confirmation biases.