I found a steal of a deal on this book at the Ellensburg fly tying expo on Saturday. Amato books was closing out both the hardbound and paperback version for $10. I got one of the remaining hardbound copies. My last two big trips were to Yellowstone in 2014 and the Metolius/Crooked River in 2015. Both times I was looking at PMD hatches and found my knowledge lacking. Here in the basin we get little running water. After a session with the book I find myself knowing much more about the nymph migrations patterns and dun emergences than before. Hopefully I have another Yellowstone trip in my near future. My guess of the reason for closing out this book is the information is too specific and doesn't have a broad appeal to anglers. It must appeal to a very specific group and didn't amount to as many sales as anticipated. Excellent book if you can get a copy and probably Amato books has the paperback version for $10.