Checking in any zone was fully legal starting in peewee hockey in Minnesota (11/12y old?) when I played back in the late '90s. I was even complimented by Bryan 'Butsy' Erickson at one of his summer camps as being one of the best players at checking he'd ever seen (at that level, of course). Unfortunately, the same could not be said of my skating ability. Thus, I was out of hockey by the time bantams rolled around, lol.