USACampsites
This is a camp site,campground directory for all types camping facilities in the United States. Listed here are Private State and Federal run camps for RV's,Tents,Pop ups and cabins. Check this out.

KOA Kampgrounds
Find over 500 campgrounds listing. Search for campgrounds with various facilities is available. You can buy national parks pass here.

GoCampingAmerica
User friendly site.You can find a campground,RVpark directory,weather,map,and general travel information for a state of your choice. Regionally divided state map and brief description of campgrounds will help you choose a right campground.

American Camping Association
Interesting camp search. You can select a camp by category including your philosophy, physical and metal problems you might have, fee and etc. You can get information on camps and contacts with description for your selection, but no camp addresses and maps are available.

National Park Foundation
This site is specialized in national park search. If you look for a national park, this is the site you want to check out. A brief road map is offered for each national park.

Gateway to the National Park Service
You can actually make a reservation at some of national parks from this site. Entrance and recreation fee information can be useful. Park listing is same as National Park Foundation, but this site additionally offers each state park agency listing

Camping-USA National Camping Grounds
This site is still in the experimental stage, but it has detail information on available campgrounds in states. Search by city/state or name.

ReserveAmerican.com
This site has a listing of campgrounds in four states; CA, NY, TX, WA. If you look for campgrounds in those four states, this site is good for you. You can also make a reservation at some campgrounds here.

StateByStateCamping
You will find this site useful in selecting parks. It offers lots of links for camping destinations in states such as a link to each State Parks &Recreation Department and to national park search. You can also find web pages of some campgrounds.

Happy Camping
This site offers a full list of campgrounds by region in states. Since only phone numbers of campgrounds are offered, call campgrounds you selected for more information.