The recent high water on the Bighorn River has caused some fly fishers to embrace different techniques in order to be successful, especially when there are swarms of emerald shiners being washed out of the reservoir and into the river.
I am ahead of myself a tad so allow me to digress just a bit. In 1995 the Bighorn River rose to 14,500 cubic feet per second, which was the most I had ever seen. (I started guiding on the river in 1985).
What I found out in 1995 was the same that I have observed in all high water years: the trout relocate to relatively calm spots along the current and wait for food to be brought to them. The food items that are conveyed along the currents are basically the same, but some new or less-common foods are also introduced.
In 1995 I was guiding a couple of anglers. The flow had been kicked up 1,000 cfs or so that morning and there was a lot of detritus floating down the river. I anchored along a run on the south side of the river and my anglers waded into the water a bit to nymph fish the run.
As I suspected, the fishing was slow because the trout weren't settled in to the new feeding lanes. My anglers landed a couple of trout but the fishing wasn't what I would term “red hot.”
Lo and behold my guide buddy, Dale Davisson, pulled out on the opposite river bank with his clients. In no time Davisson's anglers were catching one trout every five to 10 minutes. They had several doubles and didn't seem to have lulls in the fishing action. Their success and my anglers' lack of success was rather embarrassing to me so I loaded up my anglers and floated downstream.
The next morning I ran into Davisson and asked him, “What were you fishing with in the Five Dollar Hole yesterday?"
Davisson replied, “Woolly Buggers.”
“Baloney,” I snorted. “I could see the strike indicators on the lines.”
“Yup, we were fishing the Woolly Buggers as nymphs,” Davisson answered calmly.
I mulled Davisson's answer in my mind many times since that day, and I have to give him credit. When a tailwater stream — or freestone stream for that matter — has a rapid increase in flow, aquatic invertebrates are often washed out of their safe spots. There are plenty of leeches in the Bighorn River but I seldom encounter them except when the flow is kicked up.
Not only are leeches washed into the current but so are sowbugs, scuds, cranefly larvae and aquatic worms.
Nowadays in addition to the aforementioned critters, we find emerald shiners being added to the river food menu.
I have noticed my compatriots fishing white streamers that resemble the shiners, but they are using methods unlike the standard cast tight to cover and strip the sinking streamer back toward the boat.
One method involves fishing a streamer that has a foam body and letting it drift along as a dry fly. My good buddy Harrison Cummings even fishes such a streamer much like a grasshopper pattern with a beadhead Sowbug dropper trailed about a foot or so behind it; a different hopper-dropper setup, so to speak. Cummings contends that this works well on the upper three miles of the river but isn't very successful below that point, mainly because the dead and dying emerald shiners usually don't make it past Three Mile Access.
Another guide told me that he rigs two white Zonker-type streamers on a relatively short heavy leader. The leader is 20-pound test mono that is about 6-feet long. He ties a loop knot to the eye of the streamer and then about 15 inches of 0X tippet to the bend of the streamer's hook. He ties on the second streamer to the tippet. He attaches a strike indicator to the leader near the junction with the fly line and has his anglers cast toward the bank and let the flies float along like they were dead drift nymph fishing.
Another method I have heard of is fishing a standard double nymph rig with the up fly a white streamer and bottom fly a Sowbug or Scud pattern. This method calls for putting weight on the leader — for the Bighorn right now it's about two 3/0 sinkers.
Another guide likes to use a very large barrel swivel instead of a split shot. He ties it at the end of a leader, then adds heavy tippet — 0X or heavier — to his streamer and then trails it with a smaller nymph.
With the high water conditions an angler either has to adapt or stay home. I hope you will adapt and try new nymph and streamer fishing techniques. Good Luck!