Close to Great Sand Dunes, easy and free
It's basically a rocky road up the side of Mt. Blanco with lots of places to pull off and camp. Suitable for anything from the most rock-fearing to rock-ready. AT&T had a solid two+ bars. The sunset and lightning storms in the distance were breathtaking. Definitely a great choice for a night's boondocking if that's what you need.
Month of VisitAugust