Need a Colorado fishing or hunting license or swa permit, but then the camping is free. Most of the sites are more suited for RVs, but we found a great site in loop A that had plenty of room for our tents. Only 2 pit toilets for the 51 sites, 1 in B loop, and 1 in C loop, so be prepared for a long walk or a drive to get there.
All sites have covered picnic tables they do a wonderful job of blocking the sun. We were lucky that the lake was pretty high this year, although we didn't spend much time there as we came to go to the sand dunes, especially since Medano Creek was still running there.
Just a heads up, if you are tent camping and bringing your dogs, there are red ants and sand fleas around. They are most active at night. All 3 of our dogs got bit up pretty badly, but a quick talk with our vet helped us out quickly and easily. If this happens to your dog, basically all you need to do is give them 1 mg of Benadryl per lb of body weight and you can repeat every 8 hours. This won't solve the problem, but it will reduce their symptoms and once you are away from the sand for good, the bites should resolve themselves. Even the next day after the benedryl, our dogs were looking much better!