HEY Y'ALL: Civic Center Park Closes at 11pm. While it's suggested that you leave before this time and that each cruiser take upon themselves to leave no trace, you are also invited to review the guidelines for Use of a Park in Denver (as if you wanted more info).
Ultimately ignorance is not a legal defense, and none of you can now say "no one told me." Heck, we're not telling you how to behave, though it may be a good idea to be aware of what you are doing in a public space like the COD. Hey, we're just saying...

(WORD TO THE WISE: the eyes of the law are on you at the COD (no kidding hi-def camera at COD.) Thought you should know ;-)