Voting Question: What sites may I use to find good campsites in Colorado?

When I went camping the other day, I used my $50 dollar a year trails.com subscription to find a campsite. Sadly, I showed up at 3 campsites to find them all closed! Trails.com doesn't tell me if the site is closed. If it wasn't for the nice cop in Nederland, CO who drove us to an open site, we would have been SOL.
So where can I get this up-to-date information so I ensure this doesn't happen again??? Where is a place that I can find all the sites the locals know about? Trails.com doesn't even have half the hikes or sites I know exist in my beautiful state of Colorado. So please help!

Source:
http://answers.yahoo.com/question/index?qid=20110904114941AAYMDAc

tent camping tips npr campgrounds rv resort myrtle beach state park