Flowing from its headwaters in Yellowstone National Park to Three Forks, Montana, where it joins the Jefferson and the Gallatin to form the mighty Missouri, the Madison River is one of the most famous, but also one of the most complicated, trout rivers in North America. This river can have different insect hatches every fifty yards, and ranges from a glassy, spring-fed stream to a tumbling torrent filled with rapids. Its complex variety of waters and habitat defies conventional fly-fishing techniques. In Fly Fishing the Madison, fly shop owner, guide, and noted author Craig Mathews...