HELENA, Mont. -

Thanks to the Justice Department, medical marijuana businesses now have a roadmap to avoid prosecution.
    
The federal agency last week decided to allow legal pot in Colorado and Washington state. Officials say they won't intervene to block state pot laws or prosecute as long as states create strict and effective controls that follow eight conditions.
    
Medical marijuana advocates say those conditions allow states to tailor existing medical marijuana programs and give other states a guide to create new ones.
    
The DOJ's policy memo comes after voters in Colorado and Washington last fall passed first-in-the-nation laws to allow recreational pot use. In states like Montana and California, an explosion in the use of medical marijuana spawned a backlash, stricter laws and tougher federal enforcement.