The Kelley Blue Book only covers the values of snow mobiles, ATV's, motorcycles, personal watercraft, and cars; not campers, as of 2015. To determine the value of a camper, use a guide book other than the Kelley Blue Book, such as the NADA guide. Find values for campers on the NADA website.
The Kelley Blue Book is considered the standard pricing guide for cars and several other classes of vehicles. Unfortunately, they do not cover values for campers or trailers, although the company may occasionally report on them in the news section of its website. As of 2015, the Kelley website only lists values for cars, and it does not publish any speciality books on campers, despite doing so for collectible cars and older automobile models.
"Blue book" is a generic term for vehicle valuation guides, which can be the cause of some confusion, as the only guides with the phrase officially in their titles are Kelley publications. However, there are several competing groups that provide blue books for classes of vehicles not covered by Kelley. Chief among them is NADA.
The NADA provides valuations for campers, as well as cars and certain speciality vehicles such as boats. The organization is not affiliated with Kelley in any way. NADA stands for National Automobile Dealers Association, and it has been providing valuations for vehicles for almost as long as Kelley. Its publications are primarily aimed at dealers, but consumers can find camper valuations at the NADA website.