If you just want a license to be a guide, you can attend one of the courses mentioned (LL Bean also offers courses to become a Maine Guide and a place caleld Eagle Lake Camp offers a week long course where you stay there for the week - both courses include taking the written guide test. You then get scheduled to take the interview portion of the test, which, I understand, is very difficult. And it seems unlikely that they would pass someone so young - the oral test is very subjective and the administrators can simply fail you because you lack confidence).

Of course, that won' t make you fit to be a guide for other people. You' ll need lot' s more experience.

My suggestion is this: Unity College in Maine has a program (I don' t know what it' s called) that most of the people who want to be game wardens get their degree in. You could do that and then you' d be a lot more prepared to take a guide test and start working as an outfitter. You' d also have a back-up plan if you found you couldn' t make it as a guide - apply to the warden service.