I'm not having any luck finding a good one for my son.Thx.
If he'd be willing to do something with an academic leaning, you could check out the summer program at the CO School of Mines: http://www.centerforbrightkids.org/programs/summer-programs/index.html . They are not inexpensive, though.
Go to denver post's page for summer camps. It depends on your interest. We are doing some waldorf school camps, legos, and my animal lover might do one at the dumb friends league.
My kid had a great time at the denver fencing center last year:
I think they run camps all summer.
Colorado Parent Magazine has a long list of camps in the Denver area---you can find it free at libraries and grocery stores.