I'd contact the Fire Department or local USAF Public Relations office. They'd probably love to interact with younger generations if for nothing more than good PR. Getting kids active in something aviation related and outside sounds great to me but I'm not a parent there. There is plenty one can do that combines plane spotting, outdoors and the interwebs (I'm 32 so I can say that right?).

I like your enthusiasm and hope it works. Talking to the owner of the hayfield about permission to go on the land is probably a good idea if this goes forward.