I spend a lot of time writing about conventional methods of fishing high water, drifting brightly colored San Juan worms and egg patterns. There are other ways to fish. One of the most effective is to cast large streamers at the bank. This is a bit more challenging. The casting is a bit trickier and it is definitely quite a bit more work.
At low water, trout are concentrated in the main channel. When the water comes up, they move to the banks to escape the current. When we drift San Juan worms or egg patterns, we concentrate on fishing near the bank as well as submerged weed beds and sunken islands. While this is definitely effective for most trout, we need something a bit more aggressive for the larger browns. The bigger fish are more interested in bigger food sources.
You choose your rod based on the size fly you want to cast not the size fish you will be fighting. Therefore, if you are casting big streamers, you will need a bit larger rod than the cherished four weight that you use to cast dries on low water. I generally fish a nine foot six weight. A seven would work as well. I prefer a stiffer rod to help me set the hook and since I use larger tippets for larger flies I do not need as sensitive a tip to protect light tippets.
I find that floating lines are not effective for delivering large streamers in heavy water. No matter how much lead you put on the leader it is difficult to get the fly down. What I prefer is sink tips. These are floating lines that have a sinking section at the front of the line. There are a variety of sinking rates usually given in inches per second (they are also given designations as type I, type II and higher) and the sinking portions of the sink tips come in a number of lengths. I use a six weight ten foot type VI which is the fastest sinking sink tip that I can find. I find the same line handy for fishing woolly buggers in deep holes on the White River on no generation and for probing deep runs on Crooked Creek for small mouth. This rig casts like a bullet. With the heavy tip and small running line you can shoot line with ease. I would recommend that, if you had one more fly line than a floating one, that this should be it. There are other guides that use full sinking lines. I find them a bit more difficult to cast. You have to almost strip them in before you can begin a cast.
The rigging is deceptively easy. I have a braided loop on the end of the fly line. I take a four foot section of 3X tippet and tie a surgeons loop knot in the end of it and attach it to the line with a loop to loop connection. The short tippet does not allow the fly to ride up in the water column. It is also much easier to cast than a long leader with weight. It turns over easily. Use fluorocarbon tippet. It is a bit stronger, is abrasion resistant, and has a higher specific gravity than regular monofilament allowing it to sink faster. I tie the fly to the tippet with an improved clinch knot.
My favorite fly for this technique is the kiwi muddler. I was introduced to this when I guided Jack Dennis during the first Hooked On A Cure. It was his creation and he made good use of it that day. I also like wool head sculpins, zonkers, matukas and woolly buggers (my favorite is my copperhead, brown chenille, black tail, copper bead and flashabou and a brown grizzly hackle).. You definitely want a big fly (size 6, 8, or larger) that will cause some commotion and be noticed. Natural colors are the ticket here. Try and match the natural food base of sculpin, minnows or trout fry.
The technique is to cast to the bank and then strip the line back to the boat. When I say cast to the bank, I mean within inches of it. If you do not occasionally hook up on the bank, you are being too timid. The browns can be as close as two feet from the bank. I generally retrieve the fly with short erratic strips (think wounded minnow). Vary the retrieve until you figure out what they want. Concentrate on the water from the bank to twenty feet out. You can also work weed beds and other structure the same way.
Remember you will not catch nearly as many fish but you will hook up larger fish and the chance to land a trophy is greatly improved with this technique.