I was happy to find this book because it has better maps than the official State of Michigan brochures provided at the park gates. (1989 edition). By "better" I mean that rather than a detailed map of campground A and a detailed map of campground B, it shows the park with the relative locations of campgrounds A, B, group camping, and all amenities depicted. It provides a lot of information about park trails as well. again more complete information than most brochures. Mine is nearly 30 years out of date, but appears valid and useful to what I remember of the parks we've camped in over the past five years. I look forward to testing its information in next year's camping season.