a group of friends that i have been fishing with for the past 20 years recently had dinner together , one guy had purchased the dvd by blue ribbion flies , fishing yellowstone waters and out west, the time of year the hatches , i wasnt present for the review , but decide to purchase it on my own after the rave reviews . its a must have for the angler that wants to travel and fish that area , i highly recomended it . loaded with information ,patterns and hatches . if you get out there purchase it or go on line , they also have a dvd on patterns for the region as well.