Originally Posted by
SweetLou
It depends on the park. Some parks allow it, some don't. Some parks have restrictions on the time of year and where you are allowed to camp. For example, some parks might allow you to camp anywhere in the park, but you must be at least 200 feet from any road. It is a good idea to check prior to getting there.
In my experience, in the US, state and National Parks generally do not allow any form of dispersed camping. There may be exceptions, but I have not run into them. State and National Forests are more likely to, but it is far from universal. In general it is way harder to find a free or cheap place to camp in the East than in the rest of the country. Hiker/biker sites are the exception there in the East as well.
Still there are lots of free places. if you ask, at least in small towns and rural areas, chances of getting permission are very good. Churches, community parks, etc. are good bets. Small town police departments and fire houses are good places to ask, as has been mentioned.