If you're at a university campus and interested in hosting an event for high school math-and/or-puzzle enthusiasts, take heed: I just helped playtest the 2025 MaPP Challenge, a puzzlehunt with puzzles based on advanced math concepts (but accessible to folks who haven't yet learned such math (or maybe they learned but forgot cough a few decades ago)). I had a fun time; your local youths might have a similarly-fun time.