This fantastic book is in it's 4th or 5th printing. The reason why is because it is so comprehensive, and so thorough, and so original.
The author not only visited literally hundreds of waterfalls all listed in this book, which must have taken months of research, plus travels, and studying of topographic maps, on top of countless miles of hiking, backpacking, and even some boating. The book is also very easy to read. There are no long passages of famous quotes from naturalists of the past. Just lists of waterfalls grouped by region, making it very easy to see more than a few on one trip. Add great directions and maps on how to get there, and superb descriptions of each waterfall. He also rates the waterfalls, gives information on how worthy the view is, how easy or hard it is to get to the waterfall.
If you are a waterfall lover, or even think you're interested in seeing some, this valuable book is as good as it gets.