The Department of Justice announced that it would let Native American tribes grow or sell marijuana on their reservations, even in states where the drug is still illegal. The decision opens the door to pockets of legal marijuana throughout the country, in addition to the growing number of states that have legalized pot or are considering doing so. There are more than 300 reservations in some 30 states. If a good portion of those tribal governments choose to grow and sell marijuana on their land, then large swaths of the country will have access to legal pot. (See also: Tribes wary of selling pot, even if feds allow it)