California and western states that cozy up to the Rockies, in particular, are ground zero come summer. Reservations Rule at Commercial Campgrounds During the height of the season, the country's 8,000 commercial campgrounds typically fill up and most campers reserve their sites. Most campground owners have Web sites and you can book a site by e-mail. From the home page you can click on a map to obtain phone numbers and details about campgrounds in specific towns or areas. You can also link to more than 500 of KOA's franchise campgrounds from its Web site .
Most campgrounds fill up in summertime, so book ahead.
If you don't have access to the Internet, contact state tourism offices and ask for a list of campgrounds. It's dawn, but already the RVs are lined up to snag a coveted campsite in Yellowstone. The scene isn't unique to Yellowstone. It occurs in many of the most beautiful spots in America's national parks. Currently, there's no central number you can call to book a site anywhere in the National Park system for the reasons mentioned above.