This is the most famous Catskill river, starting at the storied Junction Pool where the upper Beaverkill and Willowemoc come together (look for the sign on Old Route 17, which parallels the river, as you head west out of Roscoe). For the next 15 miles downstream to the village of East Branch, the river offers a mix of large pools and long riffles. The pools, which are often marked by signs, bear historic names such as Barnhart's, Hendrickson's, and Cairn's, and they are usually populated with dozens of flyfishermen. Avoid the popular no-kill zones, which are clearly posted, and head to less crowded areas. The trout are everywhere, especially in the spring before the falling water levels and increasing temperatures force them to move to cool-water refuges elsewhere in the system.