On June 12th, a new law in Denver took effect which prohibits marijuana in city parks. You cannot consume, display, transfer, or grow marijuana in Denver's city parks. Public consumption has always been illegal in Denver and throughout Colorado, but this new law specifically prohibits marijuana at city parks altogether. A violation of the law results in a $150 fine, which increased fines for subsequent violations.
During the 2012 Election, the Amendment 64 campaign used the slogan 'regulate marijuana like alcohol.' The slogan was successful of course, because voters overwhelming approved the initiative. Alcohol is not prohibited at Denver city parks, which seems to not fall in line with the will of Colorado voters. If I was a city official, I would prefer marijuana to alcohol, considering the fact that alcohol consumption is associated with a lot of issues that aren't associated with marijuana.
I'm willing to concede that public consumption of marijuana in city parks in public view may not be what voters wanted. And I definitely don't think Colorado voters expected Denver parks to allow cultivation of marijuana. However, the possession of marijuana in city parks should not be illegal. How does having a nug of Colorado's finest in my pocket harm anyone else at the park?
We will see how enforcement goes. I'd imagine if people are being blatant, they will get fined. If you are being discrete and not making a big deal out of it, I don't see how cops will even know what is going on. But then again, if a cop is bored and smells marijuana in the air, there's nothing to stop him/her from shaking down people. Hopefully possession bans in parks doesn't become a trend in Colorado.