I would guess we're in the 45 and older range. I own over 100 caches in south Texas. They rarely get found until the winter when the Winter Texans show up. Then, once they're in the area, it's a feeding frenzy. There have been days when I've had over 50 found emails. BTW, I'm 50. Personally, I think this is the perfect activity for getting retired people out and about, doing something other than golf. As for us younger sorts, the same applies. I'm in Seoul, Korea now and have explored this city much more vigorously because of geocaching than if I didn't participate. Local cachers take me to wonderful spots I'd never find on my own.