[Chad Fairbanks]

Well, pretty much any violation on indian land by a non-indian becomes a federal crime...

[kingu]

Right, so long as there is a federal crime to charge them with. IE: If a tribe decides to ban smoking in cars, it would be non-enforcable for non-tribal members since there's no federal statute to defer to. Though, say, restrictions on fishing, is enforcable since there is federal laws against theft.