In answer to a formal inquiry from the Washington State Liquor Control Board, the Washington Attorney General's Office today issued an Opinion concluding that Initiative 502 does not express an intent to preempt individual jurisdictions from exercising their own authority to further control marijuana.  

The Opinion opens the door for any jurisdiction to ban or strictly limit sales, manufacturing, distribution of marijuana. 

The full Opinion is here. 

The Opinion comes on the heels of the Yakima Nation's announcement that they intend to forbid use of all 12 million acres of Yakima ceded land from any involvement in the new marijuana trade.  The Yakima Nation has filed more than 300 objections to such licensing on their lands and expects to file hundreds more.  The story is covered in this Olympian article Here