I think Rebel is correct. There is a Camp Brule (pronounced BROO-LAY) in Sullivan County. I camped there several times when I was a Boy Scout 20+ years ago. We always did the trip in January or February. Sledding, ice skating, ice hockey, football on a frozen lake with 18+ inches of snow, endless snowball fights followed by hot cocoa and a hot meal in a warm cabin with a group of friends - NOBODY ever missed that trip! If I had been able to add ice fishing to that glorious list of activities, my Mom may have had to drag me away from that camp kicking and screaming...
I am not sure if they allow non-scouters to fish there, but I do remember fishing it as a kid with some pretty fair success in the open water but never through the ice. There were pickerel, gills and perch plus it was stocked with trout. Best option is to call the camp HQ and ask or better yet, get involved with a scout troop and offer to do a weekend workshop on ice fishing with a group of kids. I'm sure it would be a weekend they'd never forget.