I'd also check into industry grant matching opportunities. Companies like Microsoft will match their employee's volunteer hours with money that goes right to your school programs - do some recruiting (MS does $25.00 per volunteer hour - that adds up quick).
I think being able to teach youth how to fly fish is so valuable, not just for the sake of learning to fish. For them to step outside and slow down to see their surroundings, to get away from the normal has to be fun to watch. Cool thing you are doing. PM sent.
If the weather allows and my back is feeling a little better I hope to be going to the show in Lynnwood next weekend. I will be dropping of a bunch of flies for a young friend in Shoreline and a couple of fly rods for you.
In my house there is a rule: buy a toy, same amount goes to charity. This is one of many examples of an opportunity. I know there are garages, closets and basements full of perfectly good fly fishing (and other) gear, some of it never even used, When I die, I do not want to explain to my maker why I had hundreds, maybe thousands of $$ in unused stuff sitting in my closet. Pay-it-forward is not just a movie, it's a lifestyle. Good on all of y'all that already know that.