The KOA in Holbrook, AZ, is conveniently located just west of Petrified Forest National Park. A quick 10-minute drive to the SW entrance will reward you with a quiet, easy entrance to the park. From there, you can drive through the park and end up at the main visitor center on the northern end, near the Painted Desert.
This campground has a nice, yet older, playground, a swimming pool (open seasonally), and offers full hookups (including cable for an extra fee), tent sites, and cabins. The "kamping kitchen" is open for cowboy cookouts, including dinner and breakfast (at extra charge), and we sampled their all-you-can-eat pancake breakfast, which was the best one our 5-year-old ate on our entire trip! Right near the kitchen is a sampling of petrified wood to get you in the spirit of exploration. The owners are very friendly, and even in June this campground felt uncrowded. Sites are a bit close together, but with our small 17-foot trailer, we had plenty of room, a picnic table, and fire ring. The owners were also helpful about giving directions and suggestions about all the attractions in the area. There is also a laundry room on site.