Summer camps for 18 year olds in Nevada/Utah/California

My friends and I are looking for a "percy-jackson" esque kind of summer camp in Nv or in the surrounding states of NV, but most of us are 18. We're looking for an overnight experience with a couple activities to do and mild weather, but it looks like the cut off for most of the major camps is 17. Anyone know of any that would take 18 year olds that sound like what we're looking for?