Overall we prefer to use a sink tip line to fish big streamers.
On rivers such as the Yellowstone, Madison and the Missouri you want you fly in specific areas and getting into the trout’s zone ASAP. Many times you are throwing into debris and rocky banks in fast water and so want to be confident you can get your fly back and hit those likely spots.
We like leaders in the 3-5 foot length. Many different recipes are out their but we recommend about 24” of 20 lbs Maxima and another 12-24” of 10-12 lbs maxima. The sink tip line will bring your fly down so you want it relatively close to the heavier “sinking line”. Unlike fishing dries or small nymphs you are trying to trigger the trout’s animal instinct to protect their area and you don’t need to worry about the trout being “leader shy”. Using these heavier leaders will not only give you confidence in not losing the trout but also throwing it into those fishy, dangerous areas such as log jams and rock piles.
Most guides we know prefer the non-slip mono knot for attaching the fly. This knot will allow the fly to have the proper movement while being attached to a very strong tippet.
To see a quick video on how to tie this knot check out this video. Tying a slip mono loop.
Covering lots of water and varying your retrieve will give you the best chance to be successful with streamers. We generally fish these big streamers from the boat and cast them close to the banks, on the drop off’s and into any likely spot that may hold a trout.
Practice. Practice. Practice.
Fishing with streamers is quite a lot of work but the rewards can be tremendous.