The Umpqua Copper John Barr's Gold Bead Fly in Chartreuse, Size 18, is a finesse nymph that shines when trout are locked onto smaller insects or are pressured by frequent angling. This compact profile sinks quickly thanks to the gold bead and segmented wire body, while the chartreuse color adds a unique twist that can make all the difference in tough conditions. Ideal for tailwaters, technical waters, or late-season fishing, the size 18 version sneaks into feeding lanes without spooking fish. Its small but deadly presence is perfect for rounding out a euro rig or trailing behind a larger attractor nymph.