The following site list various dump stations in the 48 states.? The list consist of state parks, visitor centers, Flying J and other stations.?
If you are planning a trip, you could copy and paste the various states dump stations you will be traveling.? Then print out the various states sites.? There is a book on the market that list the various dump stations.
Another book i find very useful is the REST AREA GUIDE. It has info on which rest areas that allow overniting. Also rv dump station, truck stops, and dinning choices. It's about have the size as the rv'er guide, but most of the same info. As with any publication, we have found out of date information in both the rv'ers friend, and the rest area guide. I wonder if they come from the same source. I think the most up to date and useful book is the NEXT EXIT. It list everything available on all the exits on all the interstates in the US, and Canada. Everything that is RV friendly is listed in Red.