it's kind of the same thing in the US, but with slightly more freedom. Still, it's almost impossible to find places to fly, since national parks are closed to UAV's, and historical sights are hard to come by. If you don't mind bending the law, as opposed to breaking it, you can claim ignorance as long as there is no signage clearly visible. You are, however risking a lot, because fines are high, and sometimes you can run into a strict ranger who won't buy your excuses. The #1 rule is don't disobey the word of a ranger, since you wont really have a reasonable excuse for flying otherwise.