I'm camping in one of Colorado's beautiful parks this weekend and brought the P3A. Unsure of the "rules" (even though I looked thru every CRS) I stopped a ranger to ask, expecting him to tell me I couldn't fly. He surprised me by pointing out all sorts of areas, basically any large, open area. Also said over the reservoir would be great right at dusk, just to use good judgment. He gave me his card just in case any of his fellow Rangers "gave me any trouble". Just thought I'd pass this along to anyone wondering.