For Large Western Trout Rivers (Yellowstone, Madison, Snake, Green, etc.) I use a WF-6-F floating fly line with a 14 foot front taper with a 17.7 foot front belly and a 13.7 rear belly with a 25 foot rear taper in a light green color. This line lets me fish drys as small as size 22 up to streamers as large as a size 6. It casts well in the wind and its hard finish lets me make long casts when needed.
fly sizes - large western trout rivers - 6,8,10,12,14,16,18,20,22