Places to shoot a 22lr around Sun Valley?

Going on vacation next month with my family. Looking to shoot with my 9yr son and surprise him with a 22lr. Are there any good places to shoot? I'd rather an informal place, or someplace where we could have our own bay (25 yards is enough to start). Barring an official range, are there any shooting spots. Not always a big fan, but I could highlight how NOT to shoot.

Any specific state laws about shooting on public land? I've been using google maps to find some potential places North of Sun Valley. What is it for national Forests, 100 yards from a road, IIRC?