DENVER -

A drug policy conference is being held in Denver as Colorado prepares for the first legal sales of recreational marijuana.

Dignitaries from Canada, Mexico and Uruguay are touring a Denver marijuana dispensary Wednesday. Colorado is preparing to play host for 1,000 drug policy experts and legalization backers at the International Drug Policy Reform Conference.
    
Marijuana legalization will be a major topic at the conference. Colorado and Washington state have authorized pot possession for all adults over 21, with retail sales beginning next year.
    
America's shifting marijuana policy is playing out in other nations, too. Uruguay is finalizing plans to authorize and oversee marijuana production and sales.