In reply to Charley17: We wild-camped without any problems. The only other people we saw were other walkers and climbers, and we never saw anyone who might have objected. Most of the others we met were bivvying, but we took tents as we were up there for a week. Most of the time it stayed dry, but when it rained, boy did it rain! Forget My Fair Lady, the rain in Spain falls mainly on the Picos.
The main problem is finding somewhere with a water supply.