Go to the perfect game website and look up the 17u WWBA. 400+ teams there. Go to the Bracket information and start from the top teams and work backwards.
https://www.perfectgame.org/ev...ets.aspx?event=20418
16u WWBA (400+) from this week would yield a very similar list.
https://www.perfectgame.org/ev...ets.aspx?event=20417
If you search the individual teams, you can see if they are from all over or just a "local" team. Contacting them will probably take some work.